AviationWeather

AviationWeather

Typed aviationweather.gov Data API client for Deno, Bun, Node.js and Cloudflare Workers: METAR and SPECI observations by station and time range, TAFs, and the bulk METAR cache file — raw report text next to the decoded fields, plus the remarks T-group's tenths-of-a-degree temperature that weather markets settle on.

Overview

import { AviationWeather } from '@tundraconnect/aviationweather';

const awc = new AviationWeather({ userAgent: 'my-recorder/1.0' });
const reports = await awc.getMetars({ ids: ['KNYC', 'KLGA'], hours: 6 });
for (const r of reports) {
  console.log(
    r.icaoId,
    r.metarType, // 'METAR' or 'SPECI'
    r.rawOb,
    r.remarkTemperatures.hourly?.temperatureC, // 16.1 from T01610150
  );
}

Method	Endpoint	Result
getMetars()	/api/data/metar	AviationWeatherMetar[]
getTafs()	/api/data/taf	AviationWeatherTafSchema[]
getMetarCache()	/data/cache/metars.cache.csv.gz	AviationWeatherMetarCache

Exact temperatures. The body of a METAR rounds temperature to whole degrees (16/15). US ASOS stations repeat it to 0.1 °C in the remarks T-group (T01610150 = 16.1 °C, dewpoint 15.0 °C), and synoptic-hour reports add the 6-hour maximum and minimum (10200, 20189) and the 24-hour extremes (4snTTTsnTTT). Every METAR comes back with remarkTemperatures, read from rawOb itself, and parseRemarkTemperatures() does the same for any report text you stored.

Every report, as sent. getMetars() returns every report in the range, routine METARs and SPECIs alike, with every decoded field the service sends (unmodelled ones included) and the raw text. A station with nothing in range returns [] (the service's 204). The bulk cache keeps every CSV column as the exact string in the file.

Rate limits. aviationweather.gov allows 100 requests per minute and blocks clients that go over. Each client paces its own requests to that budget (rateLimit; false turns it off) and sends a custom User-Agent (userAgent), as the service asks. A query returns at most 400 reports; for many stations, read the cache file once a minute instead.

Runtimes. No credentials. The service sends no CORS headers, so it can't be called from a browser page; everything else (Deno, Bun, Node, Cloudflare Workers, plain V8) works. The cache file needs the standard DecompressionStream.

Out of scope (for now)

• PIREPs, SIGMETs, G-AIRMETs, station/airport info and the other Data API products.
• The TAF cache file (XML only).

Documentation

Topic	Description
API	Configuration, methods and remark groups
Errors	Error codes and diagnostic metadata
Schemas	Public Guardian schemas and inferred types

Upstream

• Data API (usage rules, cache files)
• Remark groups are defined in the Federal Meteorological Handbook No. 1 (FMH-1), chapter 12.

Installation

Deno:

deno add jsr:@tundraconnect/aviationweather

Bun:

bunx jsr add @tundraconnect/aviationweather

Node.js:

npx jsr add @tundraconnect/aviationweather

Quick Start

Track the running daily high at Central Park, Midway and LAX from the bulk cache, one request a minute for all three:

import { AviationWeather } from '@tundraconnect/aviationweather';

const awc = new AviationWeather({ userAgent: 'my-recorder/1.0' });
const cache = await awc.getMetarCache({ stations: ['KNYC', 'KMDW', 'KLAX'] });
for (const row of cache.rows) {
  const t = row.remarkTemperatures;
  console.log(
    row.station_id,
    row.observation_time,
    row.metar_type,
    t.hourly?.temperatureC ?? row.temp_c, // tenths when the T-group is there
    t.sixHourMax?.temperatureC,
  );
}
console.log('cache built', cache.lastModified);

License

MIT. Part of Tundra Connect, typed vendor API clients for Deno, Bun, Node.js and Cloudflare Workers.