v2025.07.0

This release extends xarray's support for custom index classes, restores support for reading netCDF3 files with SciPy, updates minimum dependencies, and fixes a number of bugs.

Thanks to the 17 contributors to this release:
Bas Nijholt, Benoit Bovy, Deepak Cherian, Dhruva Kumar Kaushal, Dimitri Papadopoulos Orfanos, Ian Hunt-Isaak, Kai Mühlbauer, Mathias Hauser, Maximilian Roos, Miguel Jimenez, Nick Hodgskin, Scott Henderson, Shuhao Cao, Spencer Clark, Stephan Hoyer, Tom Nicholas and Zsolt Cserna

What's Changed

• new whats-new section by @mathause in #10420
• Fix Pydap tests for numpy 2.3.0 changes (scalar string to unicode) by @kmuehlbauer in #10421
• Fixed color.shape != grid.shape in streamplot when nx != ny by @scaomath in #10411
• Fix Index._repr_inline_() signature by @benbovy in #10415
• Clean up backend indexing some more by @dcherian in #10376
• Check and fix chararray string dimension names by @kmuehlbauer in #10395
• Fix reindex on Dataset from MultiIndex DataFrame with RuntimeError by @csernazs in #10381
• Apply new ruff rules by @DimitriPapadopoulos in #10428
• BUG: Fix display with nested NumPy arrays by @basnijholt in #10222
• DOC: Add cf_xarray to ecosystem page by @VeckoTheGecko in #10443
• Expose top-level xarray.indexes in init by @dcherian in #10435
• fix assert_equal for DataTree by @mathause in #10440
• Use a set comprehension by @DimitriPapadopoulos in #10453
• Redundant list comprehension can be replaced using generator by @DimitriPapadopoulos in #10454
• Simplify chained comparison between the operands by @DimitriPapadopoulos in #10447
• Unassigned string statement by @DimitriPapadopoulos in #10452
• Iterate the dictionary directly instead of calling .keys() by @DimitriPapadopoulos in #10451
• Unnecessary tuple/list literal by @DimitriPapadopoulos in #10450
• Unreachable code by @DimitriPapadopoulos in #10449
• Appending to dictionary immediately following its definition by @DimitriPapadopoulos in #10448
• Exceptions are overlapping by @DimitriPapadopoulos in #10446
• Enforce ruff/Pylint Warnings (PLW) by @DimitriPapadopoulos in #10458
• Update pre-commit hook pre-commit by @DimitriPapadopoulos in #10461
• Enforce ruff/Pylint Refactor rules (PLR) by @DimitriPapadopoulos in #10459
• Enforce ruff/Pylint Convention rules (PLC) by @DimitriPapadopoulos in #10460
• Switch to using the NumFOCUS Code of Conduct by @shoyer in #10432
• More Pylint issues by @DimitriPapadopoulos in #10463
• More f-strings, less format() by @DimitriPapadopoulos in #10474
• Enforce ruff/flake8-2020 rules (YTT) by @DimitriPapadopoulos in #10467
• assert_equal: ensure check_dim_order=False works for DataTree by @mathause in #10442
• Keyword argument passed twice by @DimitriPapadopoulos in #10473
• Branches of the if statement have similar implementation by @DimitriPapadopoulos in #10475
• Enforce ruff/flake8-simplify rules (SIM) by @DimitriPapadopoulos in #10462
• Apply assorted ruff preview rules by @DimitriPapadopoulos in #10465
• Revert "Enforce ruff/flake8-simplify rules (SIM)" by @max-sixty in #10476
• Fix RangeIndex slicing by @benbovy in #10471
• Update error message regex for latest Zarr by @dcherian in #10485
• update dependencies; drop python 3.10 by @dhruvak001 in #10438
• Fix critical np.timedelta64 encoding bugs by @spencerkclark in #10469
• Prevent pydap (dap4) to change string arrays to unicode type (testing). Fixed upstream by @Mikejmnez in #10482
• Downgrade zarr requests performance expectations for zarr 3.0.9 by @TomNicholas in #10491
• Use add_note() to annotate exceptions when encoding fails by @shoyer in #10464
• Check if zarr store supports consolidated metadata by @TomNicholas in #10457
• Fix Zarr 'number of requests' test by @ianhi in #10492
• Rename toplevel header from Contribute to Development by @scottyhq in #10472
• Release workflows: always check that the built dist is valid. by @dcherian in #10408
• Fix bug with ci/release_contributors.py script by @TomNicholas in #10494
• Release notes for v2025.07.0 by @TomNicholas in #10495

New Contributors

• @scaomath made their first contribution in #10411
• @csernazs made their first contribution in #10381
• @basnijholt made their first contribution in #10222
• @dhruvak001 made their first contribution in #10438

Full Changelog: v2025.06.1...v2025.07.0

v2025.06.1

This is quick bugfix release to remove an unintended dependency on typing_extensions. Apologies for the trouble.

What's Changed

• Guard typing_extension import by @sjperkins in #10413
• (fix): disallow NumpyExtensionArray by @ilan-gold in #10334
• (fix): ndim accessible as np.ndim on PandasExtensionArray by @ilan-gold in #10414
• Up-to-date instructions for reading & writing to Zarr with Xarray by @alxmrs in #10410
• Release 2025.06.1 by @dcherian in #10416

New Contributors

• @alxmrs made their first contribution in #10410

Full Changelog: v2025.06.0...v2025.06.1

v2025.06.0

This release brings HTML reprs to the documentation, fixes to flexible Xarray indexes, performance optimizations, more ergonomic seasonal grouping and resampling
with new SeasonGrouper and SeasonResampler objects, and bugfixes.
Thanks to the 33 contributors to this release:
Andrecho, Antoine Gibek, Benoit Bovy, Brian Michell, Christine P. Chai, David Huard, Davis Bennett, Deepak Cherian, Dimitri Papadopoulos Orfanos, Elliott Sales de Andrade, Erik, Erik Månsson, Giacomo Caria, Ilan Gold, Illviljan, Jesse Rusak, Jonathan Neuhauser, Justus Magin, Kai Mühlbauer, Kimoon Han, Konstantin Ntokas, Mark Harfouche, Michael Niklas, Nick Hodgskin, Niko Sirmpilatze, Pascal Bourgault, Scott Henderson, Simon Perkins, Spencer Clark, Tom Vo, Trevor James Smith, joseph nowak and micguerr-bopen

What's Changed

• Add xarray-lmfit extension for curve fitting to ecosystem documentation by @kmnhan in #10262
• Rename Twitter to X by @star1327p in #10283
• Add public typing.py module by @micguerr-bopen in #10215
• Adding xarray-eopf to ecosystem.rst by @konstntokas in #10289
• Add redirect for contributing guide by @scottyhq in #10282
• Add Index.should_add_coord_to_array by @benbovy in #10137
• Fix for scalar detection by @huard in #8821
• DOC: Remove reference to absolufy-imports from contributing guide by @VeckoTheGecko in #10290
• Do not rely on np.broadcast_to to perform trivial dimension insertion by @hmaarrfk in #10277
• (fix): remove PandasExtensionArray from repr by @ilan-gold in #10291
• Add SeasonGrouper, SeasonResampler by @dcherian in #9524
• dev whats-new by @dcherian in #10294
• Add back getattr for ExtensionArrays by @dcherian in #10278
• (fix): allow upcasting of nans in as_shared_dtype for extension arrays by @ilan-gold in #10292
• Fix BinGrouper when labels is not specified by @dcherian in #10295
• (fix): numeric arrow dtype deep copies by @ilan-gold in #10315
• Fix rolling mean on bool arrays by @gcaria in #10319
• Alignment of n-dimensional indexes with partially excluded dims by @benbovy in #10293
• FIX: prevent unnecessary type casts in rolling mean by @kmuehlbauer in #10341
• Remove "Y" and "M" from DatetimeUnitOptions by @spencerkclark in #10306
• fix roundtripping zero-size timedelta arrays by @kmuehlbauer in #10313
• Implement literal np.timedelta64 coding by @spencerkclark in #10101
• Set .conjugate as alias of .conj, #10302 by @joneuhauser in #10303
• Fix setuptools deprecation warnings by @gcaria in #10300
• The URL in CONTRIBUTING.md was broken and didn't automatically redirect. by @erik-mansson in #10351
• Disallow standard calendar np.datetime64 encoding prior to reform by @spencerkclark in #10352
• Docs: User Guide for Complex Numbers by @andrewendlinger in #10235
• Avoid copying vectorized indexes by @jder in #10316
• apply_ufunc: don't modify attrs on input variables by @erik-mansson in #10330
• ruff: default rule set by @DimitriPapadopoulos in #10360
• Fix "a array" misspelling by @DimitriPapadopoulos in #10365
• Apply assorted ruff/flake8-pytest-style rules (PT) by @DimitriPapadopoulos in #10363
• Apply assorted ruff/flake8-simplify rules (SIM) by @DimitriPapadopoulos in #10364
• Ignore ruff/Pyflakes rule F401 more precisely by @DimitriPapadopoulos in #10369
• Enforce ruff/refurb rules (FURB) by @DimitriPapadopoulos in #10367
• Enforce ruff/flake8-implicit-str-concat rules (ISC) by @DimitriPapadopoulos in #10368
• (fix): pandas extension array repr for int64[pyarrow] by @ilan-gold in #10317
• Apply assorted ruff/Pylint rules (PL) / Enforce PLE rules by @DimitriPapadopoulos in #10366
• Enforce ruff/flake8-pyi rules (PYI) by @DimitriPapadopoulos in #10359
• Implement cftime vectorization as discussed in PR #8322 by @antscloud in #8324
• Fix doc typo for caption "Interoperability" by @tomvothecoder in #10374
• use numpy dtype exposed by zarr array instead of metadata.data_type by @d-v-b in #10348
• Pin Mypy to 1.15 by @kmuehlbauer in #10378
• Improve html repr in dark mode (Jupyterlab + Xarray docs) by @benbovy in #10353
• Add missing AbstractWritableDataStore base methods and arguments by @sjperkins in #10343
• Enforce ruff/flynt rules (FLY) by @DimitriPapadopoulos in #10375
• Docs: Add links to getting help mermaid diagram by @scottyhq in #10324
• Grouper tweaks. by @dcherian in #10362
• html repr: improve style for dropdown sections by @benbovy in #10354
• Fix performance regression in interp from #9881 by @dcherian in #10370
• Avoid unsafe casts from float to unsigned int by @QuLogic in #9964
• DOC: Update link to Cartopy reference by @star1327p in #10386
• Update a link in ROMS_ocean_model.ipynb by @star1327p in #10394
• Automatic Dask-Zarr chunk alignment by @josephnowak in #10336
• added movement to Xarray related projects by @niksirbi in #10403
• Update concat for multi-variable indexes. by @dcherian in #10371
• Switch docs to jupyter-execute sphinx extension for HTML reprs by @scottyhq in #10383
• Adds chunk key encoding to kwargs passed to zarr by @BrianMichell in #10274
• Release v2025.06.0 by @dcherian in #10406

New Contributors

• @kmnhan made their first contribution in #10262
• @star1327p made their first contribution in #10283
• @micguerr-bopen made their first contribution in #10215
• @konstntokas made their first contribution in #10289
• @joneuhauser made their first contribution in #10303
• @erik-mansson made their first contribution in #10351
• @jder made their first contribution in #10316
• @sjperkins made their first contribution in #10343
• @niksirbi made their first contribution in #10403
• @BrianMichell made their first contribution in #10274

Full Changelog: v2025.04.0...v2025.06.0

v2025.04.0

This release brings bug fixes, better support for extension arrays including returning a
pandas.IntervalArray from groupby_bins, and performance improvements.

Thanks to the 24 contributors to this release:
Alban Farchi, Andrecho, Benoit Bovy, Deepak Cherian, Dimitri Papadopoulos Orfanos, Florian Jetter, Giacomo Caria, Ilan Gold, Illviljan, Joren Hammudoglu, Julia Signell, Kai Muehlbauer, Kai Mühlbauer, Mathias Hauser, Mattia Almansi, Michael Sumner, Miguel Jimenez, Nick Hodgskin (🦎 Vecko), Pascal Bourgault, Philip Chmielowiec, Scott Henderson, Spencer Clark, Stephan Hoyer and Tom Nicholas

What's Changed

• Add new whats-new section by @dcherian in #10190
• DOC: Remove mention of netcdf pypi package by @VeckoTheGecko in #10197
• Apply ruff preview rule RUF046 by @DimitriPapadopoulos in #10199
• Fix sparse dask repr test by @dcherian in #10200
• add scipy-stubs as extra [types] dependency by @jorenham in #10202
• Fix references to core classes in docs by @malmans2 in #10207
• Fixes dimension order in xarray.Dataset.to_stacked_array by @aFarchi in #10205
• CI: Automatic PR labelling is back by @VeckoTheGecko in #10201
• Add datatree repr asv by @Illviljan in #10214
• DatasetView.map fix keep_attrs by @mathause in #10219
• Fix broken Sphinx Roles by @philipc2 in #10225
• Fix doctests by @jsignell in #10230
• Fix mypy failures on main by @jsignell in #10232
• Add RangeIndex by @benbovy in #10076
• opendap / dap4 support for pydap backend by @Mikejmnez in #10182
• Fix: Docs generation create temporary files that are not cleaned up. by @andrewendlinger in #10238
• Remove test_dask_layers_and_dependencies by @fjetter in #10242
• Fix mypy, min-versions CI, xfail Zarr tests by @dcherian in #10255
• Switch documentation to pydata-sphinx-theme by @TomNicholas in #8708
• Support extension array indexes by @ilan-gold in #9671
• Update how-to-add-new-backend.rst by @mdsumner in #10240
• Improve alignment checks by @benbovy in #10251
• Avoid stacking when grouping by chunked array by @dcherian in #10254
• BinGrouper: Support setting labels when provided with IntervalIndex by @dcherian in #10259
• Fix infinite recursion when calling np.fix by @gcaria in #10248
• Fix benchmarks runners by @dcherian in #10265
• Shorten text repr for DataTree by @jsignell in #10139
• Fix reduction by subset of grouper dimensions by @dcherian in #10258
• BinGrouper: reduce indirection by @dcherian in #10270
• Fix convert calendar on non-temporal data in datasets by @aulemahal in #10268
• add return_scalar=False as array_wrap kwarg by @gcaria in #10264
• GroupBy: Finish eagerly_compute_group deprecation by @dcherian in #10253
• (fix): remove _getattr__ method for PandasExtensionArray by @ilan-gold in #10250
• Release notes for 2025.04.0 by @dcherian in #10272

New Contributors

• @jorenham made their first contribution in #10202
• @aFarchi made their first contribution in #10205
• @mdsumner made their first contribution in #10240

Full Changelog: v2025.03.1...v2025.04.0

v2025.03.1

This release brings the ability to specify fill_value and write_empty_chunks for Zarr V3 stores, and a few bug fixes.
Thanks to the 10 contributors to this release:
Andrecho, Deepak Cherian, Ian Hunt-Isaak, Karl Krauth, Mathias Hauser, Maximilian Roos, Nick Hodgskin (🦎 Vecko), Spencer Clark, Tom Nicholas and wpbonelli.

What's Changed

• Add dev whats-new by @dcherian in #10152
• Fix GitHub Actions badge in README by @spencerkclark in #10155
• Forbid datatree to zarr append dim by @TomNicholas in #10156
• Fix numpy advanced indexing docs link by @wpbonelli in #10160
• Update DataArray.to_zarr to match Dataset.to_zarr. by @Karl-Krauth in #10164
• Preserve label ordering for multi-variable GroupBy by @dcherian in #10151
• Move chunks-related functions to a new file by @max-sixty in #10172
• Move fit computation code to dedicated new file by @max-sixty in #10174
• Fix GroupBy first, last with flox by @dcherian in #10173
• Allow setting fill_value on Zarr format 3 arrays by @dcherian in #10161
• DataTree: sel & isel add error context by @mathause in #10154
• DOC: Update docstring to reflect renamed section (modifying Zarr stores) by @VeckoTheGecko in #10180
• Use explicit repo name in upstream wheels by @ianhi in #10181
• Fix: Correct axis labelling with units for FacetGrid plots by @andrewendlinger in #10185
• Vendor pandas to xarray conversion tests by @dcherian in #10187
• Support zarr write_empty_chunks for zarr-python 3 and up by @ianhi in #10177
• release 2025.03.1 by @dcherian in #10188

New Contributors

• @wpbonelli made their first contribution in #10160
• @andrewendlinger made their first contribution in #10185

Full Changelog: v2025.03.0...v2025.03.1

v2025.03.0

This release brings tested support for Python 3.13, support for reading Zarr V3 datasets into a :py:class:~xarray.DataTree,
significant improvements to datetime & timedelta encoding/decoding, and improvements to the :py:class:~xarray.DataTree API;
in addition to the usual bug fixes and other improvements.

Thanks to the 26 contributors to this release:
Alfonso Ladino, Benoit Bovy, Chuck Daniels, Deepak Cherian, Eni, Florian Jetter, Ian Hunt-Isaak, Jan, Joe Hamman, Josh Kihm, Julia Signell, Justus Magin, Kai Mühlbauer, Kobe Vandelanotte, Mathias Hauser, Max Jones, Maximilian Roos, Oliver Watt-Meyer, Sam Levang, Sander van Rijn, Spencer Clark, Stephan Hoyer, Tom Nicholas, Tom White, Vecko and maddogghoek

What's Changed

• add new section in whats-new.rst by @kmuehlbauer in #10011
• spelling fix: possibilites -> possibilities by @shoyer in #10023
• Duck array ops for all and any by @tomwhite in #9883
• map_over_datasets: fix error message for wrong result type by @mathause in #10016
• Use resolution-dependent default units for lazy time encoding by @spencerkclark in #10017
• DOC: Fix 404 on Cubed's documentation by @VeckoTheGecko in #10029
• use mean of min/max years as offset in calculation of datetime64 mean by @kmuehlbauer in #10035
• Fix dataarray drop attrs by @j-haacker in #10030
• Start splitting up dataset.py by @max-sixty in #10039
• Upgrade mypy to 1.15 by @max-sixty in #10041
• implement map_over_datasets kwargs by @kmuehlbauer in #10012
• run CI on python=3.13 by @keewis in #9681
• Add Coordinates.from_xindex method (+ refactor API doc) by @benbovy in #10000
• Add types stubs to optional dependencies by @max-sixty in #10048
• Flexible coordinate transform by @benbovy in #9543
• More precisely type pipe methods by @chuckwondo in #10038
• Default to phony_dims="access" in h5netcdf-backend by @kmuehlbauer in #10058
• More permissive Index typing by @benbovy in #10067
• Restrict fastpath isel indexes to the case of all PandasIndex by @benbovy in #10066
• deprecate cftime_range() in favor of date_range(use_cftime=True) by @Maddogghoek in #10024
• Generalize lazy backend indexing a little more by @dcherian in #10078
• Another reduction in the size of dataset.py by @max-sixty in #10088
• Prune data tree for Isomorphic operations by @kobebryant432 in #10097
• Skip failing array api test. by @dcherian in #10102
• Pass node path to tokenize in open_datatree by @slevang in #10100
• Fix false timedelta decoding SerializationWarning and improve warning message by @spencerkclark in #10072
• Add typos check to pre-commit hooks by @max-sixty in #10040
• Ensure KeyError raised for zarr datasets missing dim names by @oliverwm1 in #10025
• Improve handling of dtype and NaT when encoding/decoding masked and packaged datetimes and timedeltas by @kmuehlbauer in #10050
• fix and supress some test warnings by @mathause in #10104
• Update asv badge url in README.md by @sjvrijn in #10113
• Fix broken Zarr test by @dcherian in #10109
• Pin pandas stubs by @jsignell in #10119
• Use to_numpy in time decoding by @dcherian in #10081
• explicitly cast the dtype of where's condition parameter to bool by @keewis in #10087
• Better uv compatibility by @max-sixty in #10124
• Change python_files in pyproject.toml to a list by @max-sixty in #10127
• Don't skip tests when on a mypy branch by @max-sixty in #10129
• Fix type issues from pandas stubs by @max-sixty in #10128
• Refactor compatibility modules into xarray.compat package by @max-sixty in #10131
• Refactor modules from core into xarray.computation by @max-sixty in #10132
• Split apply_ufunc out of computation.py by @max-sixty in #10133
• Refactor concat / combine / merge into xarray/structure by @max-sixty in #10134
• Fix test_distributed::test_async by @fjetter in #10138
• Refactor datetime and timedelta encoding for increased robustness by @spencerkclark in #9498
• [docs] DataTree cannot be constructed from DataArray by @mathause in #10142
• Fix open_datatree when decode_cf=False by @ianhi in #10141
• Fix version in requires_zarr_v3 fixture by @TomNicholas in #10145
• Adds open_datatree and load_datatree to the tutorial module by @eni-awowale in #10082
• Update flaky pydap test by @dcherian in #10149
• Use flox for grouped first, last. by @dcherian in #10148
• Refactor calendar fixtures by @dcherian in #10150
• Refactoring/fixing zarr-pyhton v3 incompatibilities in xarray datatrees by @aladinor in #10020
• Release 2025.03.0 by @dcherian in #10143

New Contributors

• @j-haacker made their first contribution in #10030
• @chuckwondo made their first contribution in #10038
• @Maddogghoek made their first contribution in #10024
• @kobebryant432 made their first contribution in #10097
• @oliverwm1 made their first contribution in #10025
• @ianhi made their first contribution in #10141

Full Changelog: v2025.01.2...v2025.03.0

v2025.01.2

This release brings non-nanosecond datetime and timedelta resolution to xarray, sharded reading in zarr, suggestion of correct names when trying to access non-existent data variables and bug fixes!

Thanks to the 16 contributors to this release: Deepak Cherian, Elliott Sales de Andrade, Jacob Prince-Bieker, Jimmy Westling, Joe Hamman, Joseph Nowak, Justus Magin, Kai Mühlbauer, Mattia Almansi, Michael Niklas, Roelof Rietbroek, Salaheddine EL FARISSI, Sam Levang, Spencer Clark, Stephan Hoyer and Tom Nicholas

What's Changed

• dev whats-new by @dcherian in #9936
• Remove outdated quantile test. by @dcherian in #9945
• Relax nanosecond datetime restriction in CF time decoding by @kmuehlbauer in #9618
• fix upstream dev issues by @kmuehlbauer in #9953
• Suggest the correct name when no key matches in the dataset by @Illviljan in #9943
• cast type to PDDatetimeUnitOptions by @kmuehlbauer in #9963
• Update time coding tests to assert exact equality by @spencerkclark in #9961
• remove dask-expr from CI runs, fix related tests by @kmuehlbauer in #9971
• Use zarr-fixture to prevent thread leakage errors by @kmuehlbauer in #9967
• fix weighted polyfit for arrays with more than 2 dimensions by @malmans2 in #9974
• Fix test_doc_example on big-endian systems by @QuLogic in #9949
• Remove unnecessary a article by @salahelfarissi in #9980
• Fix some typing by @dcherian in #9988
• Use flox for grouped first, last by @dcherian in #9986
• Add shards to valid_encodings to enable sharded Zarr writing by @jacobbieker in #9948
• Add shxarray to the xarray ecosystem list by @strawpants in #9995
• Remove repetitive that (replace it with the) by @salahelfarissi in #9994
• Enable DataTree.to_zarr(compute=False) by @slevang in #9958
• Add time_unit argument to CFTimeIndex.to_datetimeindex by @spencerkclark in #9965
• fix mean for datetime-like using the respective time resolution unit by @kmuehlbauer in #9977
• Enable passing a CFTimedeltaCoder to decode_timedelta by @spencerkclark in #9966
• Revert "Use flox for grouped first, last (#9986)" by @dcherian in #10001
• Fix infer_freq, check for subdtype "datetime64"/"timedelta64" by @kmuehlbauer in #9999
• Migrate Zarr region="auto" tests to a class by @dcherian in #9990
• Fix the push method when the limit parameter is bigger than the chunk… by @josephnowak in #9940
• Use freq="D" instead of freq="d" in pd.timedelta_range by @spencerkclark in #10004
• cast numpy scalars to arrays in NamedArray.from_array by @keewis in #10008
• remove outdated type-ignores by @kmuehlbauer in #10006
• Preserve order of variables in combine_by_coords by @kmuehlbauer in #9070
• Add FAQ answer about API stability & backwards compatibility by @TomNicholas in #9855
• release notes: 2025.01.2 by @kmuehlbauer in #10007

New Contributors

• @salahelfarissi made their first contribution in #9980
• @jacobbieker made their first contribution in #9948
• @strawpants made their first contribution in #9995

Full Changelog: v2025.01.1...v2025.01.2

v2025.01.1

This is a quick release to bring compatibility with the Zarr V3 release. It also includes an update to the time decoding
infrastructure as a step toward enabling non-nanosecond datetime support.

What's Changed

• split out CFDatetimeCoder, deprecate use_cftime as kwarg by @kmuehlbauer in #9901
• Fix zarr upstream tests by @dcherian in #9927

Full Changelog: v2025.01.0...v2025.01.1

v2025.01.0

This release brings much improved read performance with Zarr arrays (without consolidated metadata), better support for additional array types, as well as bugfixes and performance improvements.
Thanks to the 20 contributors to this release:
Bruce Merry, Davis Bennett, Deepak Cherian, Dimitri Papadopoulos Orfanos, Florian Jetter, Illviljan, Janukan Sivajeyan, Justus Magin, Kai Germaschewski, Kai Mühlbauer, Max Jones, Maximilian Roos, Michael Niklas, Patrick Peglar, Sam Levang, Scott Huberty, Spencer Clark, Stephan Hoyer, Tom Nicholas and Vecko

What's Changed

• Add blank What's New by @Illviljan in #9817
• Upgrade ruff to 0.8.0 by @DimitriPapadopoulos in #9816
• Improved duck array wrapping by @slevang in #9798
• Use compute instead of load in plot by @Illviljan in #9818
• Described default centre argument behaviour in rolling functions by @JanukanS in #9819
• Fix type annotations for get_axis_num (GH 9822) by @bmerry in #9827
• Test type annotations for Variable.get_axis_num by @bmerry in #9832
• FIX: gracfully handle missing seaborn dependency by @scott-huberty in #9835
• move ensure_dtype_not_object from conventions to backends by @kmuehlbauer in #9828
• Fixed function links in dataarray.py and dataset.py by @JanukanS in #9850
• Fix seed for random test data. by @dcherian in #9844
• Set zarr_format for zarr.consolidate_metadata by @dcherian in #9848
• Reference ncdata in docs. by @pp-mo in #9847
• Add Pyproject pre-commit hooks by @VeckoTheGecko in #9840
• dask tests: Avoid check for non-copies, xfail pandas comparison by @dcherian in #9857
• Avoid local functions in push by @fjetter in #9856
• Add token to codecov by @max-sixty in #9865
• Remove deprecated behavior for non-dim positional args by @max-sixty in #9864
• Fix/silence upstream tests by @dcherian in #9879
• finalize deprecation of "closed"-parameter by @kmuehlbauer in #9882
• Fix upstream Zarr compatibility by @dcherian in #9884
• Fix interpolation when non-numeric coords are present. by @dcherian in #9887
• Use integers instead of randint by @Illviljan in #9889
• Add "unit"-parameter to date_range, enhance iso time parser to us by @kmuehlbauer in #9885
• Add missing DataTree attributes to docs by @maxrjones in #9876
• move scalar-handling logic into possibly_convert_objects by @kmuehlbauer in #9900
• remove unused "type: ignore" comments in test_plot.py by @kmuehlbauer in #9904
• Optimize idxmin, idxmax with dask by @dcherian in #9800
• Cache pre-existing Zarr arrays in Zarr backend by @d-v-b in #9861
• Explicitly configure ReadTheDocs build to use conf.py by @shoyer in #9908
• Skip dask rolling by @Illviljan in #9909
• Rewrite interp to use apply_ufunc by @dcherian in #9881
• friendlier error messages for missing chunk managers by @keewis in #9676
• Edit serialization error message by @VeckoTheGecko in #9916
• Enhance and move ISO-8601 parser to coding.times by @kmuehlbauer in #9899
• fix warning from scipy backend guess_can_open on directory by @germasch in #9911
• time coding refactor by @kmuehlbauer in #9906
• Whats-new 2025.01.0 by @dcherian in #9919

New Contributors

• @JanukanS made their first contribution in #9819
• @bmerry made their first contribution in #9827
• @pp-mo made their first contribution in #9847
• @fjetter made their first contribution in #9856
• @d-v-b made their first contribution in #9861
• @germasch made their first contribution in #9911

Full Changelog: v2024.11.0...v2025.01.0

v2024.11.0

What's Changed

• New blank whatsnew after v2024.10.0 by @TomNicholas in #9679
• Fix inadvertent deep-copying of child data in DataTree by @shoyer in #9684
• Raise ValueError for unmatching chunks length in DataArray.chunk() by @lkstrp in #9689
• Typing annotations for arithmetic overrides (e.g., DataArray + Dataset) by @shoyer in #9688
• Add DataTree.persist by @slevang in #9682
• Use the same function to floatize coords in polyfit and polyval by @aulemahal in #9691
• Refactor out utility functions from to_zarr by @dcherian in #9695
• update mypy to 1.13 by @headtr1ck in #9687
• add pydap-server dependencies to environment.yml by @kmuehlbauer in #9709
• DOC: mention attribute peculiarities in docs/docstrings by @kmuehlbauer in #9700
• GroupBy(chunked-array) by @dcherian in #9522
• Fix writing of DataTree subgroups to zarr or netCDF by @shoyer in #9677
• Add missing xarray.core.missing import by @shoyer in #9714
• Fix groupby tests by @dcherian in #9716
• Move to micromamba 2 by @kmuehlbauer in #9732
• Enforce ruff/pygrep-hooks rules (PGH) by @DimitriPapadopoulos in #9729
• Apply ruff/flake8-pie rules (PIE) by @DimitriPapadopoulos in #9726
• Apply ruff/flake8-implicit-str-concat rules (ISC) by @DimitriPapadopoulos in #9722
• Apply ruff/flake8-simplify rules (SIM) by @DimitriPapadopoulos in #9727
• support for additional scipy nd interpolants by @hollymandel in #9599
• Fix typos found by codespell by @DimitriPapadopoulos in #9721
• Aplpy ruff rules (RUF) by @DimitriPapadopoulos in #9731
• chmod -x by @DimitriPapadopoulos in #9725
• Apply ruff rule RUF007 by @DimitriPapadopoulos in #9739
• Enforce ruff/Perflint rules (PERF) by @DimitriPapadopoulos in #9730
• Enforce ruff/flake8-comprehensions rules (C4) by @DimitriPapadopoulos in #9724
• Enforce ruff/flake8-pie rules (PIE) by @DimitriPapadopoulos in #9740
• MNT: use new conda-forge package pydap-server by @kmuehlbauer in #9741
• Reorganise ruff rules by @DimitriPapadopoulos in #9738
• pin array-api-strict<=2.1 by @kmuehlbauer in #9751
• Use micromamba 1.5.10 where conda is needed by @kmuehlbauer in #9737
• Apply ruff/flake8-simplify rule SIM401 by @DimitriPapadopoulos in #9749
• Discard useless !s conversion in f-string by @DimitriPapadopoulos in #9752
• http:// → https:// by @DimitriPapadopoulos in #9748
• Updates to Dask page in Xarray docs by @scharlottej13 in #9495
• Dispatch to Dask if nanquantile is available by @phofl in #9719
• Compress PNG files by @DimitriPapadopoulos in #9747
• Specify copyright holders in main license file by @TomNicholas in #9756
• CI runs ruff instead of pep8speaks by @DimitriPapadopoulos in #9759
• rewrite the min_deps_check script by @keewis in #9754
• unpin array-api-strict as issues are resolved upstream by @kmuehlbauer in #9762
• Fix html repr indexes section by @benbovy in #9768
• Use map_overlap for rolling reductions with Dask by @phofl in #9770
• Optimize polyfit by @dcherian in #9766
• Allow wrapping np.ndarray subclasses by @slevang in #9760
• fix cf decoding of grid_mapping by @kmuehlbauer in #9765
• Optimize ffill, bfill with dask when limit is specified by @josephnowak in #9771
• add 'User-Agent'-header to pooch.retrieve by @kmuehlbauer in #9782
• Fix open_mfdataset for list of fsspec files by @phofl in #9785
• Add download stats badges by @headtr1ck in #9786
• Buffer types by @headtr1ck in #9787
• rolling.construct: Add sliding_window_view_kwargs to pipe arguments down to sliding_window_view by @dcherian in #9720
• Add prettier and pygrep hooks to pre-commit hooks by @Armavica in #9644
• Namespace-aware xarray.ufuncs by @slevang in #9776
• Bump minimum versions by @dcherian in #9796
• Soft import by @scott-huberty in #9561
• Add utility for opening remote files with fsspec by @jrbourbeau in #9797
• Add GroupBy.shuffle_to_chunks() by @dcherian in #9320
• Minor format tweak to unrecognized engine error by @jrbourbeau in #9809
• Compatibility with Zarr v3b2 by @dcherian in #9795
• Faster chunk checking for backend datasets by @dcherian in #9808
• Add note on DataTree.map_over_datasets to migration guide by @TomNicholas in #9804
• ListedColormap: don't pass N colors by @mathause in #9811
• release notes for v2024.11.0 by @dcherian in #9794

New Contributors

• @lkstrp made their first contribution in #9689
• @scharlottej13 made their first contribution in #9495
• @scott-huberty made their first contribution in #9561

Full Changelog: v2024.10.0...v2024.11.0