National Weather Service API
- Free allowance
- Open data with no fee, no key and no registration: forecasts, alerts and observations for the United States from api.weather.gov; a User-Agent header is required and the request rate limit is not published.
- Verdict
- ★ qualifiesusable as stated; the read path was probed
- Cost
- free tier
- Identity
- anonymousno card, no phone
- Binding limit
- request-rateunverified: the rate limit is not published; over it the API answers an error that can be retried after the limit clears, typically within 5 seconds
- Evidence
- documented18 sources; a first-party page was read and the sentence quoted
- Freshness
- stale on 2026-12-03checked 2026-11-02 (live); stale on 2026-12-03
| Free tier | Open data with no fee, no key and no registration: forecasts, alerts and observations for the United States from api.weather.gov; a User-Agent header is required and the request rate limit is not published. unit requests; metered on request-count; Station observations are kept for 7 days and alerts for 7 days; a point outside the United States answers HTTP 404. Bulk path: the NOMADS server (120 hits a minute per IP address, counted across the NCEP hosts) and the NOAA Open Data Dissemination buckets on cloud platforms, open to the public; NWS alert archives are held by NCEI. |
|---|---|
| Price | none stated |
| Limits |
|
| Binding | request-rate The only stated limit is the unpublished request rate. |
| Identity | anonymous No sign-up and no key: a User-Agent string, which can be anything and may carry a contact, is the only identification; the vendor plans to replace it with an API key. |
| Egress | not applicable |
| Retention | station observations are retained for 7 days and alerts for the past 7 days (7 days) |
| Interface | rest REST over HTTPS at api.weather.gov (GeoJSON, JSON-LD, DWML, CAP and ATOM by the Accept header); an OpenAPI 3.1 specification is published at api.weather.gov/openapi.json |
| Tooling | any HTTP client that sets a User-Agent; OpenAPI specification for generated clients |
| Composes with | A keyless official US forecast and alert source; pair with api.met.no for coordinates outside the United States and with NOAA's NODD buckets for model files. |
| Reliability | A request without a User-Agent answers HTTP 403; over the unpublished limit the API errors and recovers after about 5 seconds. |
| Notes | Bulk path: NOMADS and the NODD cloud buckets; no dump through the API itself. |
| Evidence note | documented Terms are read from first-party pages; keyless points and forecast calls answered HTTP 200 and a non-US point answered HTTP 404; the rate limit was not driven. |
| Parsed numbers |
|
Evidence 18
| date | source | what it proved |
|---|---|---|
| 2026-11-02 | www.weather.gov/documentation/services-web-api | the API is open data with no fee |
| 2026-11-02 | www.weather.gov/documentation/services-web-api | the rate limit is unpublished |
| 2026-11-02 | www.weather.gov/documentation/services-web-api | over the limit a request errors and can be retried, typically within 5 seconds |
| 2026-11-02 | www.weather.gov/documentation/services-web-api | a User-Agent is the only identification |
| 2026-11-02 | www.weather.gov/documentation/services-web-api | an API key is planned |
| 2026-11-02 | www.weather.gov/documentation/services-web-api | station observations are kept 7 days |
| 2026-11-02 | www.weather.gov/documentation/services-web-api | alerts reach back 7 days |
| 2026-11-02 | api.weather.gov/openapi.json | the User-Agent string does not change limits |
| 2026-11-02 | weather-gov.github.io/api/general-faqs | a request without a User-Agent answers 403 |
| 2026-11-02 | probe: https://api.weather.gov/points/38.8894,-77.0352 | a points call with no key answered the forecast URL for the grid |
| 2026-11-02 | probe: https://api.weather.gov/points/38.8894,-77.0352 | the points call answered HTTP 200 |
| 2026-11-02 | probe: https://api.weather.gov/gridpoints/LWX/96,70/forecast | a forecast call with no key answered HTTP 200 |
| 2026-11-02 | probe: https://api.weather.gov/points/59.91,10.75 | a point outside the United States answers 404, so coverage is limited |
| 2026-11-02 | probe: https://api.weather.gov/points/59.91,10.75 | the out-of-coverage call answered HTTP 404 |
| 2026-11-02 | www.weather.gov/media/notification/pdf2/scn21-32nomad_change | NOMADS and the NCEP ftp hosts allow 120 hits a minute per IP address |
| 2026-11-02 | www.noaa.gov/information-technology/open-data-dissemination | NOAA model and radar data are published on cloud platforms |
| 2026-11-02 | registry.opendata.aws/noaa-gfs-bdp-pds/ | NODD data are open to the public |
| 2026-11-02 | raw.githubusercontent.com/public-apis/public-apis/master/REA | listed under Weather in public-apis with no auth |
Unknown values 2
- egress terms: the field does not apply to this kind of offer
- per object cap stated: the field does not apply to this kind of offer