🌤️ Free Open-Source Weather API | Open-Meteo.com

Free weather forecast and historical weather API — 30+ models, historical weather from 1940, no API key required.
Weather models from over 15 national weather services — ECMWF, DWD, NOAA, Météo-France, JMA, KMA, KNMI, DMI, MeteoSwiss, UK Met Office, BOM, CMA, and GeoSphere Austria. The best_match option automatically picks the highest-resolution model for any location. Individual models can be selected directly for model comparisons or model-specific pipelines.
Resolution ranges from 1–2 km (regional mesoscale models) to 9–11 km (global models). All output is normalised to hourly resolution and optimised to the requested coordinates.
Most global models update every 6 hours. High-resolution regional models such as ICON-D2 and AROME update every 1–3 hours. Each update ingests the latest observations from weather stations, radiosondes, aircraft, radar, and satellites.
15-minutely data is available for Central Europe and North America, interpolated from hourly model output elsewhere.
Four complementary historical datasets — each suited to a different use case:
The full server codebase is on GitHub under the AGPLv3 licence. You can self-host your own instance for unlimited API calls — useful for high-volume ML workloads or air-gapped environments.
All data served by the API is licenced under CC BY 4.0 — free to use and redistribute, including for commercial purposes, with attribution.
No API key, no sign-up, no credit card. Non-commercial use up to 10,000 daily API calls is free. Attribution is required under the CC BY 4.0 data licence.
For commercial use or higher call volumes, subscription plans are available with rate-limit increases and priority support.
All APIs use plain HTTP GET requests with query parameters and return JSON. No SDK or authentication is required for non-commercial use. Parameters are consistent across forecast and historical weather APIs — the same variable names, unit options, and output formats work everywhere.
CSV and XLSX output formats are also available. Multiple locations can be queried in a single request by providing comma-separated coordinate lists. Full parameter reference is in the documentation.
New models, variables, and APIs are announced on the blog and X. Subscribe to get release notes and changelog updates.