Observation

Overview

AEMET OpenData provides access to historical daily, monthly, and annual climatological values, as well as real-time (observación convencional) hourly observations, from AEMET’s station network across Spain. A free API key is required; request one at opendata.aemet.es.

Set the API key via the WD_AUTH__AEMET=<api_key> environment variable or the Settings(auth={"aemet": "<api_key>"}) argument.

AEMET limits each request to a date range of at most 6 months for daily values, or 3 years (36 months) for monthly/annual values; wider ranges are automatically split into multiple requests under the hood.

The hourly resolution is real-time data: it does not accept a date range at all and does not offer historical backfill — AEMET always returns whatever rolling window of recent observations (typically the last ~24h) it currently holds for the station.

AEMET enforces a strict per-minute rate limit (HTTP 429) and has also been observed to intermittently drop connections outright or have sustained outages. Requests hitting a transient failure are retried automatically with a short backoff (a couple of retries, a few seconds each), so a single call can take somewhat longer than usual if AEMET is briefly rate limiting or flaky. This is deliberately modest, not an attempt to wait out a sustained outage — if AEMET is down for longer than that, the request fails rather than hanging for minutes.

License

Data is © AEMET. See AEMET OpenData for further information and usage conditions.