Fetch an aggregated historical or future daily weather summary for a date using OpenWeather's One Call API 3.0 day_summary endpoint
domain: api.openweathermap.org · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Call GET https://api.openweathermap.org/data/3.0/onecall/day_summary with lat, lon, date (YYYY-MM-DD), and your API key.
Optionally add a tz parameter (±HH:MM) if the automatically detected timezone for the coordinate is incorrect for your use case.
Parse the aggregated fields: min/max/morning/afternoon/evening/night temperatures, humidity, precipitation, cloud cover, and wind.
Note the supported date range spans from January 2, 1979 through roughly 1.5 years of forecast into the future.
Confirm your OpenWeather subscription is on the 'One Call by Call' plan, since One Call 3.0 (including day_summary) is billed separately from the older 2.5 product family.
Known gotchas
One Call 3.0 requires a specific 'One Call by Call' subscription — legacy free-tier API keys for other OpenWeather products don't automatically authorize this endpoint.
day_summary returns aggregated daily statistics, not hourly detail — use the main onecall endpoint's hourly/daily blocks if finer granularity is needed.
Requesting dates far outside the 1979-to-present-plus-1.5-years window will fail; verify date bounds before batch-requesting historical ranges.
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