Free Weather APIs with no API key

22 Weather APIs that need no API key, account or credit card. 13 of them also allow CORS, so you can call them straight from browser JavaScript. Listed by uptime and ease of use.

1
NASA POWER API
Online · 228 ms
Global solar and weather data for energy and agriculture.
- No API key needed
- Fast: 228 ms response
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
2
Veabird API
Online · 587 ms
Beach (sargassum, waves, hurricanes) and ski snow forecasts for 1,900+ resorts, no key.
- No API key needed
- Returns JSON at its URL
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
3
Open-Meteo API
Online · 522 ms
Global weather forecast API for non-commercial use.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
4
Open-Meteo Ensemble API
Online · 523 ms
Weather ensemble forecasts from multiple models.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
5
Pirate Weather API
Online · 419 ms
Free weather API with forecast data similar to Dark Sky.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
6
WeatherTotals API
Online · 491 ms
Measured US snow, rain, hail and aurora totals by state and city.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
7
wttr.in API
Online · 454 ms
Weather in your terminal, supports JSON output.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
8
Terrace Weather API
Online · 782 ms
Terrace open/closed verdict for restaurants, from the weather forecast.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
9
US Weather API
Online · 927 ms
US National Weather Service. A free weather API by weather.gov.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
10
FMI Open Data API
Online · 1444 ms
Finnish weather, sea, climate and radar observations via open WFS.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
11O
openSenseMap API
Online · 637 ms
Data from Personal Weather Stations called senseBoxes.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
12
World Time & Weather API
Online · 543 ms
Current weather, local time, UTC offset and DST rules for 400 cities as static JSON.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
13
RainViewer API
Online · 726 ms
Radar data collected from different websites across the Internet.
- No API key needed
- HTTPS
No authHTTPSCORS ?
14H
Hail History API
Online · 1890 ms
Radar-detected hail history for any US address from NOAA NEXRAD Level-III hail detections, by year.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
15I
IPMA API
Online · 788 ms
Portuguese weather and climate data.
- No API key needed
- HTTPS
No authHTTPSCORS ?
16
weather-api
Online · 1025 ms
A RESTful free API to check the weather.
- No API key needed
- HTTPS
No authHTTPSNo CORS
17
AviationWeather API
Online · 2077 ms
NOAA aviation weather forecasts and observations.
- No API key needed
- HTTPS
No authHTTPSCORS ?
18N
NOAA CO-OPS API
Online · 994 ms
US coastal tides, water levels, currents and meteorological observations.
- No API key needed
- HTTPS
No authHTTPSCORS ?
19
Hong Kong Obervatory API
Online · 1284 ms
Provide weather information, earthquake information, and climate data.
- No API key needed
- HTTPS
No authHTTPSCORS ?
20
7Timer! API
Online · 266 ms
Weather, especially for Astroweather. A free weather API by 7Timer!.
- No API key needed
- Fast: 266 ms response
No authNo HTTPSCORS ?
21M
Meltema API
Last check failed
Multi-model weather: GFS, ECMWF AIFS/IFS and a 31-member GEFS ensemble, keyless point forecasts.
- No API key needed
- HTTPS
No authHTTPSNo CORS
22
ODWeather API
Last check failed
Weather and weather webcams. A free weather API by oceandrivers.com.
- No API key needed
No authNo HTTPSCORS ?

Keyless Weather APIs compared

Weather APIs with no API key
API	API key	HTTPS	CORS	Uptime	Response	Rating
NASA POWER	No	Yes	Yes	Up	228 ms	Not rated
Veabird	No	Yes	Yes	Up	587 ms	Not rated
Open-Meteo	No	Yes	Yes	Up	522 ms	Not rated
Open-Meteo Ensemble	No	Yes	Yes	Up	523 ms	Not rated
Pirate Weather	No	Yes	Yes	Up	419 ms	Not rated
WeatherTotals	No	Yes	Yes	Up	491 ms	Not rated
wttr.in	No	Yes	Yes	Up	454 ms	Not rated
Terrace Weather	No	Yes	Yes	Up	782 ms	Not rated
US Weather	No	Yes	Yes	Up	927 ms	Not rated
FMI Open Data	No	Yes	Yes	Up	1444 ms	Not rated
openSenseMap	No	Yes	Yes	Up	637 ms	Not rated
World Time & Weather	No	Yes	Yes	Up	543 ms	Not rated
RainViewer	No	Yes	Unknown	Up	726 ms	Not rated
Hail History	No	Yes	Yes	Up	1890 ms	Not rated
IPMA	No	Yes	Unknown	Up	788 ms	Not rated
weather-api	No	Yes	No	Up	1025 ms	Not rated
AviationWeather	No	Yes	Unknown	Up	2077 ms	Not rated
NOAA CO-OPS	No	Yes	Unknown	Up	994 ms	Not rated
Hong Kong Obervatory	No	Yes	Unknown	Up	1284 ms	Not rated
7Timer!	No	No	Unknown	Up	266 ms	Not rated
Meltema	No	Yes	No	Down	–	Not rated
ODWeather	No	No	Unknown	Down	–	Not rated

FAQ

Are there free Weather APIs without an API key?

Yes. 22 free Weather APIs need no API key or sign-up, including NASA POWER API, Veabird API and Open-Meteo API. You can send a request straight away.

Which keyless Weather APIs can I call from JavaScript in the browser?

13 of them also support CORS, including NASA POWER API, Veabird API and Open-Meteo API, so a plain fetch from a web page works.

Do APIs without a key have limits?

Usually, yes. Keyless APIs typically rate-limit by IP address, so cache responses and avoid tight loops. For production traffic, an API with a free key tier often gives higher, more predictable limits.