Agent tools · Last verified 2026-10-15

Open-Meteo weather API for AI agents

Forecasts and current conditions for any latitude/longitude. No key for non-commercial use.

What it does

Open-Meteo serves weather forecasts, current conditions and historical data for any coordinates as plain JSON. You pick the variables you want (temperature, wind, precipitation and so on), so responses stay small, which suits agents with limited context.

Verified facts

PriceFree for non-commercial use; commercial use requires a paid plan. [Verified 2026-10-15] source
API key / authNot required for the free non-commercial API. [Verified 2026-10-15] source
Rate limitFewer than 10,000 calls/day, 5,000/hour and 600/minute on the free tier. [Verified 2026-10-15] source
TermsFree tier is non-commercial use only, as defined in Open-Meteo terms (Creative Commons framing). Commercial products need a paid plan. [Verified 2026-10-15] source
EndpointGET https://api.open-meteo.com/v1/forecast?latitude=…&longitude=… [Verified 2026-10-15] source

Prompt to give your agent

When I ask about weather, call the Open-Meteo API (no key): https://api.open-meteo.com/v1/forecast?latitude=<lat>&longitude=<lon>&current=temperature_2m,wind_speed_10m&daily=precipitation_sum&timezone=auto. Look up coordinates yourself if I give a city name. Report units exactly as returned. This is for personal, non-commercial use.

Agent / MCP-style tool snippet

// Agent tool definition (JSON Schema) — implement with HTTP GET
{
  "name": "open_meteo_forecast",
  "description": "Current weather and forecast from Open-Meteo. Free for non-commercial use. No API key.",
  "input_schema": {
    "type": "object",
    "properties": {
      "latitude": { "type": "number" },
      "longitude": { "type": "number" },
      "current": { "type": "string", "description": "Comma-separated variables, e.g. temperature_2m,wind_speed_10m" }
    },
    "required": ["latitude", "longitude"]
  }
}
// GET https://api.open-meteo.com/v1/forecast?latitude={lat}&longitude={lon}&current={current}

Working example (run 2026-10-15)

curl -sS "https://api.open-meteo.com/v1/forecast?latitude=40.71&longitude=-74.01&current=temperature_2m,wind_speed_10m"

Response (trimmed):

HTTP 200
{"latitude":40.710335,"longitude":-73.99308,"timezone":"GMT",
  "current_units":{"temperature_2m":"°C","wind_speed_10m":"km/h"},
  "current":{"time":"2026-10-15T19:45","temperature_2m":18.8,"wind_speed_10m":7.4}}

When not to use it

  • Do not use the free tier inside a commercial product — Open-Meteo’s terms require a paid plan for commercial use.
  • Do not treat it as an aviation or marine official source; it is a forecast API, not certified METAR/TAF delivery.
  • Do not exceed free-tier rate limits (10,000/day, 5,000/hour, 600/minute) without moving to a paid plan.

Use cases

  • Trip and event planning assistants
  • Daily briefing agents
  • Adding weather context to personal dashboards

FAQ

Is Open-Meteo free?

Yes for non-commercial use, with under 10,000 calls per day. Commercial use needs a paid plan.

Does Open-Meteo need an API key?

Not for the free non-commercial API.

Alternatives

  • Wikipedia REST API — Free text facts when you need place context, not live weather numbers.
  • Openverse API — Free licensed media search when the agent needs sounds or images instead of weather.
  • Open-Meteo docs (paid tiers) — Same vendor’s commercial options when the free non-commercial terms do not fit.

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