open-meteo

• You need weather forecasts (hourly/daily/current) for coordinates.
• You need air quality / pollen forecasts (hourly/current) for coordinates.
• You need to resolve a user-provided place name to coordinates and timezone (geocoding).
• You need to support multi-location batching (comma-separated lat/lon lists).
• You need a deterministic checklist for Open-Meteo query parameters, response parsing, and error handling.

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.

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

1. 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.

1. 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.

1. 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.

1. 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.

1. Implement robust request/response handling

- Treat HTTP errors and JSON-level errors separately.

- JSON error format is:

- {"error": true, "reason": "..."}

- When requesting multiple locations (comma-separated coordinates), expect the JSON output shape to change to a list of structures.

- Optionally use format=csv or format=xlsx when you need data export.

1. Validate correctness with a “known city” check

- Geocode “Berlin” → Forecast hourly=temperature_2m for 1–2 days → verify timezone and array lengths.

- Air Quality hourly=pm10,pm2_5,european_aqi → verify units and presence of hourly_units.

• Do not include out-of-scope APIs in this skill’s implementation guidance: Historical Weather, Ensemble Models, Seasonal Forecast, Climate Change, Marine, Satellite Radiation, Elevation, Flood.
• Do not omit timezone when requesting daily variables (per docs).
• Do not assume unixtime timestamps are local time; they are GMT+0 and require utc_offset_seconds adjustment.
• Do not silently ignore {"error": true} responses; fail fast with the provided reason.
• Do not request huge variable sets by default; keep queries minimal to reduce payload and avoid accidental overuse.

• You can geocode a place name and obtain coordinates/timezone.
• You can fetch Forecast data with at least one hourly, one daily (with timezone), and one current variable.
• You can fetch Air Quality data for at least one pollutant and one AQI metric.
• Your client code handles both HTTP-level failures and JSON-level error: true with clear messages.
• Attribution requirements from the docs are captured for Air Quality (CAMS) and Geocoding (GeoNames).

• Official docs (in-scope):

- https://open-meteo.com/en/docs

- https://open-meteo.com/en/docs/air-quality-api

- https://open-meteo.com/en/docs/geocoding-api

• Skill references:

- references/forecast-api.md

- references/models.md

- references/weather-codes.md

- references/air-quality-api.md

- references/geocoding-api.md

- references/examples.md