OpenWeather One Call API vs The Weather Company Data APIs

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.

The Weather Company Data APIs

A wide weather data API with 168 API references built from OpenAPI documents, global 4 km current conditions, hourly history from June 2015 and a status page with component history. Keys come only through a sales-reviewed trial or contract, travel only in the URL, and the terms that govern the API are not published.

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

The Weather Company Data APIs

1. Send units, language and format=json with a location on every v3 call, plus Accept-Encoding: gzip, which the usage guide marks as required.
2. Keep the key out of logs and client-side code, because it travels in the query string as apiKey.
3. Treat a 401 as either a bad key, an endpoint outside the key's package or an exceeded limit, and treat a 204 as no data for the query.
4. Each forecast duration (3day to 15day) is a separate entitlement. Request only durations the contract covers.
5. Use /v3/aggcommon to combine up to 10 products in one request. Each product and each location still counts as one call.