Look up which CIMIS data provider (station network vs spatial grid) covers a given California zip code before querying ET data
domain: et.water.ca.gov · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Call GET https://et.water.ca.gov/api/station to list all WSN weather stations with their StationNbr, active date range, and associated ZipCodes array.
Call GET https://et.water.ca.gov/api/stationzipcode (or /api/stationzipcode/{zip}) for WSN-supported zip codes, and /api/spatialzipcode (or /{zip}) for SCS-supported zip codes.
Cross-reference a target zip against both lists: if it appears in both, your data request's prioritizeSCS flag decides whether you get the 2km-grid SCS values or the nearest physical WSN station's readings.
If a zip appears in neither list, don't attempt a data request for it — you will get a 404 (ERR1031 UNSUPPORTED ZIP CODE).
Prefer querying by station number directly (from /api/station) over zip code when you need guaranteed WSN-only data, such as hourly items.
Known gotchas
SCS zip coverage is based on 2010 census zip polygons, so very new zip codes may be unsupported by SCS even in populated areas.
A single WSN station can serve multiple zip codes (see the ZipCodes array on /api/station), so station-level and zip-level data for "the same area" are not always identical.
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