Open-Meteo
Global weather forecast API for non-commercial use
- Authentication
- No auth
- HTTPS
- Yes
- CORS
- Yes
- Category
- Weather
- Data source
- public-apis + marcelscruz
- Documentation / URL
- https://open-meteo.com/
Overview
Open-Meteo is a free, open-source weather API that combines forecast data from official national weather services — including NOAA GFS, ECMWF, DWD, MeteoFrance and Met Office — into a single, consistent JSON endpoint. No API key is required, which makes it one of the easiest weather APIs to start with.
It is listed as free for non-commercial use; for commercial projects check the current terms on the official site.
What you can get
- Current weather — temperature, wind speed and direction, WMO weather code, is-day flag
- Hourly & daily forecasts — temperature, precipitation, humidity, pressure, UV index, soil moisture and more
- Historical weather — ERA5 reanalysis data back to 1940
- Air quality (AQI), marine weather and geocoding endpoints
- 12+ forecast models, configurable per request
Quick Start
A single call gets current weather for any latitude/longitude:
curl "https://api.open-meteo.com/v1/forecast?latitude=52.52&longitude=13.41¤t_weather=true"The response is compact JSON:
{
"latitude": 52.52,
"longitude": 13.42,
"current_weather": {
"time": "2026-08-22T03:45",
"temperature": 21.3,
"windspeed": 12.6,
"winddirection": 234,
"is_day": 1
}
}Useful parameters:
| Parameter | Purpose |
|---|---|
current_weather=true |
current conditions |
hourly=temperature_2m,precipitation |
hourly forecast series |
daily=temperature_2m_max,temperature_2m_min |
daily min/max |
timezone=auto |
local timezone of the coordinates |
temperature_unit=fahrenheit |
unit switch (default celsius) |
Authentication
None. Open-Meteo works without registration or an API key — just send requests.
CORS & HTTPS
HTTPS is supported and CORS is enabled, so you can call Open-Meteo directly from the browser (fetch in client-side JavaScript works without a proxy).
Rate Limits & Notes
- Free for non-commercial use; the free tier allows a generous number of daily requests (exact quota on the official site).
- Respect fair use: add a short cache to avoid hammering the API from every page view.
- Data comes from official weather services; latency and update cadence vary by model.
FAQ
Does Open-Meteo require an API key? No — Open-Meteo is a no-auth API, you can call it directly.
Is Open-Meteo free for commercial use? It is listed for non-commercial use — check open-meteo.com for the current commercial terms before building a paid product on it.
Can I call it from the browser? Yes. CORS is enabled and HTTPS is supported, so client-side calls work without a proxy.