a simple and robust weather api using dark sky for client-side or server-side js
Clone or download
Latest commit 7a46045 Nov 2, 2018



A simple and robust isomorphic js wrapper library for Dark Sky API (previously known as Forecast.io).


  • Simple to use.
  • Promise based (es6-promises).
  • Lightweight browser location checking (by default).
  • Isomorphic - use it client-side or server-side.
  • Versatile - use it statically or instantiate it.
  • Dates returned as moments.
  • Excludes are used automatically to reduce latency and save cache space (see 'Request Parameters').

See Dark Sky developer docs: https://darksky.net/dev/docs.

Need something even smaller? dark-sky-api uses dark-sky-skeleton.

You can use dark-sky-api client-side OR server-side. Note: an example of a server side proxy used with client side dark-sky-api is forthecoming...

Install it

 npm install dark-sky-api

Import it

import DarkSkyApi from 'dark-sky-api';

or Common JS

const DarkSkyApi = require('dark-sky-api');

Configure it

Static configuration is suggested.

DarkSkyApi.apiKey = 'your-dark-sky-api-key';

Proxy URL - Client-side be warned!

The above is simple and great for testing, but your api key is exposed in every request (when running in client-side). Using a separate server-side proxy to make the actual api call to dark sky is highly suggested as this hides the api key. [ref].

To use a proxy set your api-key to false or an empty string, and pass the URL of the proxy service as the proxy (second) param.

DarkSkyApi.proxy = '//base-url-to-proxy/service'; 

Experimental (help wanted)

dark-sky-api theoretically supports a proxy service (aka untested). A proxy service would receive a request issued by dark-sky-api, attach this query to a base URI (like the following: https://api.darksky.net/forecast/your-api-key), and return a final request.

Running Server Side

Along with your api key, set proxy to true.

DarkSkyApi.apiKey = 'your-dark-sky-api-key';
DarkSkyApi.proxy = true; 

Passing true as the proxy parameter indicates that the caller is server-side. Awesome!

Optional Configuration

DarkSkyApi.units = 'si'; // default 'us'
DarkSkyApi.language = 'de'; // default 'en'
DarkSkyApi.postProcessor = (item) => { // default null;
  item.day = item.dateTime.format('ddd');
  return item;

Use it

Today's weather:

  .then(result => console.log(result));

Forecasted week of weather:

  .then(result => console.log(result));

Specific time request:

  .then(result => console.log(result));

What about geo location?

By default dark-sky-api will use Geolocation.getCurrentPosition to grab the current browser location automatically.

To manually set geolocation position pass along a position object. This is mandatory when running dark-sky-api server-side!

const position = {
  latitude: 43.075284, 
  longitude: -89.384318
  .then(result => console.log(result));

Retrieve the current location from the browser.

let position;
  .then(pos => {
    position = pos;

loadPosition takes an optional options param.

Response units

To get the units used in dark sky api responses per configured unit type (default is 'us') use GetResponseUnits after configuration. Keep in mind that the units would need to be retrieved again if you changed the api units.

const responseUnits = DarkSkyApi.getResponseUnits();
  .then((data) => {
    console.log(`The temperature is ${data.temperature} degrees ${responseUnits.temperature}`);
    console.log(`The wind speed is ${data.windSpeed} ${responseUnits.windSpeed}`);

Extend Hourly

Use extendHourly to return hour-by-hour data for the next 168 hours, instead of the next 48.

// turn on

// turn off

Post Processor

The post processor method is mapped to all weather items. It's an easy way to add or manipulate responses for an app.

// import
import DarkSkyApi from 'dark-sky-api';

// configure
DarkSkyApi.apiKey = 'my-api-key';
DarkSkyApi.postProcessor = (item) => { // must accept weather data item param

  // add a nice date representation using moment.calender
  item.dayNice = item.dateTime.calendar(null, {
    sameDay: '[Today]',
    nextDay: 'ddd',
    nextWeek: 'ddd',
    lastDay: '[Yesterday]',
    lastWeek: '[Last] ddd',
    sameElse: 'ddd'

  // add units object onto item
  item.units = DarkSkyApi.getResponseUnits(); // this would be outdated if you changed api units later

  return item; // must return weather data item

// use 
  .then(data => console.log(data.dayNice)); // Today

Time Machine request

To retrieve weather data for a specfic point in time use loadTime. See docs for more info.

DarkSkyApi.loadTime(time, position);

Time can be a moment or a formatted date string.

const time = moment().year(2000);
DarkSkyApi.loadTime(time) // or '2000-04-06T12:20:05' aka moment.format()
  .then(result => console.log(result));

Hourly, Minutely, Alerts, and Flags

To retrieve any of these results use loadItAll with optional excludesBlock. ExcludesBlock indicates which data points to omit.

DarkSkyApi.loadItAll(excludes, position);


DarkSkyApi.loadItAll('daily,hourly,minutely,flags') // just return alerts

Creating an instance

If you need to maintain multiple instances (configurations) of dark-sky-api create an instance.

// import
import DarkSkyApi from 'dark-sky-api';

// instantiate
const api = new DarkSkyApi(apiKey, proxy, units, language, processor); // only apiKey or proxy are required

// instance config methods support method chaining
  .postProcessor(item => {
    item.newProp = val;
    return item;

// extend hourly available for forecasts

// turn off extend hourly

// change position
position = {
  latitude: 43.075284, 
  longitude: -89.384318

// change back
api.loadPositionAsync() // get current position
  .then(position => api.position(position));

// time machine request

Initialization / Configuration

Tldr: Initialization of the api is automatic, but configure before making api calls.

Static configuration settings such as apiKey, proxy, units, language, and postProcessor are set prior to initialization (configuration phase), locked in during initalization (implicit or explicit), and can be changed after initialization.

Implicit (suggested)

This happens automatically when making a method call such as loadCurrent, loadForecast, loadTime or loadItAll. Remember to configure beforehand.

// configuration code 
DarkSkyApi.apiKey = 'my-api-key';

// api call somewhere else
DarkSkyApi.loadCurrent(); // initialized automatically


DarkSkyApi.apiKey = 'my-api-key';


DarkSkyApi.initialize(apiKey, proxy, units, language, postProcessor); // only apiKey or proxy are required

Change/set configuration after initialization/use

It's possible to change units, language, postProcessor, extendHourly, and time after initialization. Note: calling any of the static set[Config] methods will initialize the api so make sure you've added an api key or proxy before using them.

DarkSkyApi.apiKey = 'my-api-key';

// config after initialization
DarkSkyApi.setPostProcessor((item) => { 
  return {
    temperature: item.temperatureMax || item.temperature,
    icon: item.icon

// can only be set after initialization


Troubleshooting steps:

Shim Promise

.then()/.catch()/.finally()/etc isn't available in all browsers. Make sure and add a promise shim.


add a shim. I like core-js npm install core-js

require in your build require('core-js/es6/promise');

To Do

  • add position validation
  • add hourly and minutely api methods
  • add flags and alerts api methods
  • add tests