Open-Meteo
Free open-source weather API with no key required.
About
Open-Meteo is a free weather API that combines output from national weather services like ECMWF, NOAA's GFS, the German DWD's ICON, and Meteo-France, picking the best model per location. It needs no API key or account: a single GET request returns current conditions plus hourly and daily forecasts as clean JSON, with separate endpoints for geocoding, air quality, marine, and historical data back to 1940.
The server code is open source and the processed model data is published as open data, so teams can self-host the whole API. The free tier is for non-commercial use under CC-BY 4.0 with attribution, capped around 10,000 calls per day; commercial use needs a license. It has become the default weather backend for prototypes, IoT firmware, and AI weather demos precisely because there is no signup friction.
What it can do
- Current, hourly, and 16-day forecasts as JSON
- Multi-model blending from national weather services
- Free geocoding, air quality, and marine endpoints
- Open-source server for self-hosting
Setup
Call https://api.open-meteo.com/v1/forecast with latitude and longitude; no key needed.
Prerequisites
Coordinates or use the free geocoding endpoint.
Use cases
Works with
Trust score — 8/10
Scored 8/10 (verified tier, metrics-v1). Evidence: Verified via vendor site/docs/GitHub and reputable coverage, wave 96; Trending score 76/100 from researcher assessment.
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.