Met Office Weather DataHub (Site Specific) vs OpenWeather One Call API

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.

OpenWeather One Call API

1,000 free calls a day, then $0.0015 a call, or $0.001 on the agent lane. The main API takes the key only as the appid query parameter.

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

OpenWeather One Call API

1. Sign up on the agent lane with POST https://agents.openweathermap.org/v1/accounts and keep the data key. It's shown once
2. Check GET https://data.openweathermap.org/account/balance for credit. No data response carries a cost or balance
3. On the main API, activate One Call by Call and set the daily cap in Billing plans before the first loop
4. Pass units=metric. The default is Kelvin
5. Use exclude=minutely,alerts on 3.0, or the 4.0 timeline step you need, to shrink responses