open-meteo

Open Meteo

Goal

Provide a reliable, production-friendly way to call Open-Meteo APIs (Forecast, Air Quality, Geocoding), choose variables, control time/units/timezone, and parse responses consistently.

Steps

1. Pick the correct API and base URL

   • Forecast: https://api.open-meteo.com/v1/forecast
   • Air Quality: https://air-quality-api.open-meteo.com/v1/air-quality
   • Geocoding: https://geocoding-api.open-meteo.com/v1/search

2. Resolve coordinates (if you only have a name)

   • Call Geocoding with name and optional language, countryCode, count.
   • Use the returned latitude, longitude, and timezone for subsequent calls.

3. Design your time axis (timezone, timeformat, and range)

   • Prefer timezone=auto when results must align to local midnight.
   • If you request daily=..., set timezone (docs: daily requires timezone).
   • Choose timeformat=iso8601 for readability, or timeformat=unixtime for compactness.
     • If using unixtime, remember timestamps are GMT+0 and you must apply utc_offset_seconds for correct local dates.
   • Choose range controls:
     • forecast_days and optional past_days, or
     • explicit start_date/end_date (YYYY-MM-DD), and for sub-daily start_hour/end_hour.

4. Choose variables minimally (avoid "download everything")

   • Forecast: request only the variables you need via hourly=..., daily=..., current=....
   • Air Quality: request only the variables you need via hourly=..., current=....
   • Keep variable names exact; typos return a JSON error with error: true.

5. Choose units and model selection deliberately

   • Forecast units:
     • temperature_unit (celsius / fahrenheit)
     • wind_speed_unit (kmh / ms / mph / kn)
     • precipitation_unit (mm / inch)
   • Forecast model selection:
     • default models=auto / “Best match” combines the best models.
     • you can explicitly request models via models=....
     • provider-specific forecast endpoints also exist (provider implied by path). See references/models.md (section "Endpoints vs models=") for examples and doc links.
     • for provider/model-specific selection tradeoffs, see references/models.md.
   • Air Quality domain selection:
     • domains=auto (default) or cams_europe / cams_global.