Google Weather API (Maps Platform) vs Met Office Weather DataHub (Site Specific)

Google Weather API (Maps Platform)

Covered by the Maps Platform SLA, 99.9 per cent with service credits. History is 24 hours only, and bulk data isn't available.

Met Office Weather DataHub (Site Specific)

Statutory UK weather service, with a FAQ licence to copy, publish and adapt the data. No OpenAPI, llms.txt, SDK or MCP server.

Google Weather API (Maps Platform)

1. Ask for only the days or hours you need, one location a call. Every call is one billable event
2. Page with pageSize and pageToken rather than asking for 240 hours at once
3. Check the coverage page before promising alerts. Coverage is by country
4. Refetch rather than cache. The Maps terms give no caching window for weather content
5. Restrict the key to the Weather API and your server IPs in the Cloud console

Met Office Weather DataHub (Site Specific)

1. Register an application and subscribe it to the Global Spot plan first. The key is tied to that order and shown once
2. Send the key in the apikey header with Accept: application/json, and latitude and longitude as query parameters
3. Add excludeParameterMetadata=true to drop the parameter descriptions from every response
4. Pick the timestep by need. hourly covers 48 hours, three-hourly 168, daily 7 days, and each call counts against the daily limit
5. Stop on a 429. The limit is daily and resets at 00:00 UTC