Free vs Paid Weather Services APIs for AI Agents the best free upstreams in any category.

Very far. National met offices publish openly across much of the world — vedurstofa-mcp serves Icelandic forecasts, warnings, and earthquakes from vedur.is; mcp-server-taiwan-weather wraps Taiwan's Central Weather Administration; the NOAA family of servers covers US marine and storm modeling in depth. Open-Meteo aggregates global model data with a free tier for non-commercial use.

For an agent answering 'will it rain tomorrow in Reykjavik,' there is no reason to pay anyone. The data is public, the servers are open source, and coverage is genuinely global.

Free weather upstreams carry conditions worth reading. Some, like Open-Meteo, distinguish non-commercial from commercial use — check the current terms before shipping a product on a free tier. Government APIs are reliable but unprioritized: no SLA, occasional maintenance windows, and rate limits designed for polite use, which a fleet of agents polling forecasts can exceed.

And free sources serve standard products. Hyperlocal nowcasting, route-specific forecasts, or derived indices for agriculture — the territory agrobr touches with Brazilian crop and climate data — often involve processing someone has to fund.

Paid weather endpoints make sense in three cases: commercial licensing (your product resells forecasts and the free tier's terms exclude that), guaranteed delivery (your agent's decisions are time-critical and you need someone accountable for uptime), and value-added processing (custom models, blended sources, domain-specific outputs).

x402 fits these as per-call purchases: the agent requests a forecast, gets an HTTP 402 with the price, pays in USDC, and receives the data — settled on Base in about two seconds, from $0.01 per call. For a logistics agent checking marine conditions per voyage rather than per minute, per-call pricing is exactly proportional to need.

Default to free: the open servers over NOAA, Open-Meteo, and national met offices cover most agent use cases at zero cost. Pay when your use is commercial under the upstream's terms, when you need an operator on the hook for delivery, or when the forecast itself is a processed product rather than public data.

Loomal's Weather Services category lists all 59 live servers with descriptions and x402 pricing where maintainers have configured it, making the free-by-default landscape easy to scan.