Weather APIs
Free weather APIs with working curl examples: hourly and daily forecasts, current conditions, air quality and city geocoding. No credit card, most need no API key.
18 tested APIs with full docs · 18 need no key · 39 more listed
Tested, with full documentation
We called each of these before publishing. Every page carries a working curl command, the real JSON response it returned, parameters and common errors.
7Timer!
Free 7Timer! API with no key: astronomical seeing, transparency and cloud cover forecasts for stargazing, plus general weather. No signup. Tested example.
Bright Sky (DWD)
Free Bright Sky API with no key: current weather, hourly forecasts and historical records from Germany's national weather service, back to 2010. Tested.
Open-Meteo Historical Archive
Free historical weather API with no key: hourly and daily weather for any location worldwide going back to 1940, from ERA5 reanalysis data. Tested example.
Hong Kong Observatory
Free Hong Kong weather API with no key: current readings by district, rainfall, warnings and forecasts from the territory's official meteorological service. Tested example included.
IPMA (Portugal)
Free Portuguese weather API with no key: five-day city forecasts from the national meteorological institute, plus seismic and warning datasets. Tested example included.
Open-Meteo Marine
Free marine weather API with no key: wave height, wave period and direction, swell and sea surface temperature forecasts worldwide. Tested curl example.
MET Norway Locationforecast
Free Norwegian Meteorological Institute weather API with no key: hourly global forecasts with temperature, wind, pressure and precipitation. Tested example.
Meteo.lt
Free Lithuanian weather API with no key: hourly long-term forecasts from the national service, with feels-like temperature, gusts and condition codes. Tested example included.
NOAA NCEI Natural Hazards
Free natural hazards API with no key: NOAA's historical tsunami, significant earthquake and volcanic eruption databases, filterable by year, region and magnitude. Tested example included.
NOAA National Weather Service
Free US National Weather Service API with no key: official forecasts, active severe weather alerts, radar stations and observations. Government source. Tested.
Open-Meteo Air Quality
Free air quality API with no key: PM2.5, PM10, ozone, nitrogen dioxide, European and US AQI plus pollen forecasts worldwide. Tested curl example included.
Open-Meteo
Free weather forecast API with no API key and no signup. Hourly and daily forecasts worldwide, free for commercial use. Working curl example and live response.
Open-Meteo Geocoding
Free geocoding API with no key: convert a city or place name into latitude and longitude, with population, country and timezone. Tested curl example and live JSON.
openSenseMap
Free citizen weather station API with no key: read any senseBox's sensors and their latest measurements, from temperature and humidity to particulates. Tested example included.
RainViewer
Free weather radar API with no key: a manifest of past and forecast radar frames worldwide, each resolving to standard map tiles you can overlay. Tested example included.
Environment Canada GeoMet
Free Canadian weather API with no key: OGC API - Features access to climate stations, daily and hourly records, and forecasts, as standards-compliant GeoJSON. Tested example included.
World Time & Weather
Free city data API with no key: local time, UTC offset, explicit DST rules and monthly climate normals for hundreds of cities, as static JSON. Tested example included.
wttr.in
wttr.in is a free console-oriented weather API with no key. Get weather as plain text, ASCII art, PNG or full JSON with one curl command. Live example included.
Choosing between these Weather APIs
Weather is the single most requested category of public API, and it is also where free tiers vary the most. The APIs below were each called live before publishing, so the endpoints, parameters and response shapes on every page reflect what the service returns today — not what a README claimed years ago.
If you only need a forecast without signing up for anything, start with Open-Meteo: it requires no API key, allows commercial use on the free tier and returns clean JSON. MET Norway is the other genuinely free option, though it requires a descriptive User-Agent header identifying your app.
More Weather APIs in the directory
39 further APIs in this category, of which 10 need no API key. These are catalogued from the public-API lists and link straight to each provider's own documentation — we have not tested them yet, so treat the auth and CORS flags as the upstream list's claim rather than ours. They are promoted to a full tested page as we work through them.
| API | What it does | Auth |
|---|---|---|
| AccuWeather | Weather and forecast data | Key |
| Aemet | Weather and forecast data from Spain | Key |
| APIXU | Weather | Key |
| AQICN | Air Quality Index Data for over 1000 cities | Key |
| AviationWeather | NOAA aviation weather forecasts and observations | None |
| ColorfulClouds | Weather | KeyCORS |
| Data Commons | Open source initiative from Google. Global disaster events and statistics data | Key |
| Euskalmet | Meteorological data of the Basque Country | Key |
| Foreca | Weather | OAuth |
| GISTDA | Thailand natural disaster information | Key |
| GribStream | Global weather forecast API for any use. Leverage the NBM and GFS models. Great for bulk pulls | Key |
| Hail History | Radar-detected hail history for any US address from NOAA NEXRAD Level-III hail detections, by year | NoneCORS |
| HG Weather | Provides weather forecast data for cities in Brazil | KeyCORS |
| Hong Kong Obervatory | Provide weather information, earthquake information, and climate data | None |
| IPMA | Portuguese weather and climate data | None |
| Korea Meteorological Administration | Weather and climate data from KMA | Key |
| Meltema | Multi-model weather: GFS, ECMWF AIFS/IFS and a 31-member GEFS ensemble, keyless point forecasts | None |
| Met Office DataPoint | Weather data for the UK | Key |
| Meteoblue | Global weather data with 100+ weather variables, 14 days ahead and 4 days of history data. | KeyCORS |
| Meteorologisk Institutt | Weather and climate data | Key |
| Meteosource | Global weather forecasts based on machine learning and historical data | Key |
| Micro Weather | Real time weather forecasts and historic data | Key |
| NOAA NGDC | Natural hazards data including earthquakes, tsunamis, and volcanic eruptions | None |
| ODWeather | Weather and weather webcams | None |
| Oikolab | 70+ years of global, hourly historical and forecast weather data from NOAA and ECMWF | KeyCORS |
| OpenUV | Real-time UV Index Forecast | Key |
| OpenWeatherMap | Weather | Key |
| Pirate Weather | Free weather API with forecast data similar to Dark Sky | NoneCORS |
| QWeather | Location-based weather data | KeyCORS |
| Rainbow Weather | Global real-time nowcasting API powered by radar + satellite fusion | Key |
| Storm Glass | Global marine weather from multiple sources | KeyCORS |
| Tomorrow | Weather API Powered by Proprietary Technology | Key |
| US Weather | US National Weather Service | NoneCORS |
| Visual Crossing | Global historical and weather forecast data | KeyCORS |
| weather-api | A RESTful free API to check the weather | None |
| WeatherAPI | Weather API with other stuff like Astronomy and Geolocation API | KeyCORS |
| Weatherbit | Weather | Key |
| Weatherstack | Real-Time & Historical World Weather Data API | Key |
| Yandex.Weather | Assesses weather condition in specific locations | Key |