open-meteo-mcp

MCP server for Open-Meteo — free weather APIs, no API key required.

Features

• 16 tools covering weather forecast, historical data, air quality, marine, flood, ensemble, climate projections, and scheduled data collection
• Scheduled jobs — server-side cron, persists readings to SQLite, returns aggregated stats
• No auth — Open-Meteo is free for non-commercial use
• stdio transport — works with Claude Desktop and any MCP client

Tools

Weather data

Tool	Description
geocode	Search locations by name → lat/lon, timezone, country
get_forecast	7–16 day forecast, hourly + daily (45+ variables)
get_historical	ERA5 reanalysis from 1940 to present
get_air_quality	PM2.5, PM10, ozone, NO2, SO2, CO, pollen, EU/US AQI
get_marine	Wave height, period, direction, swell, sea surface temp
get_elevation	Elevation above sea level, batch up to 100 points
get_flood	GloFAS river discharge forecast, up to 16 weeks
get_ensemble	Multi-model ensemble with uncertainty quantification
get_climate	CMIP6 climate projections 1950–2050
get_seasonal	ECMWF SEAS5 seasonal forecast up to 9 months
get_dwd_icon	DWD ICON model — high-res for Europe
get_ecmwf	ECMWF IFS model — gold standard global forecast

Weather comparison

Tool	Description
compare_weather_cities	Compare named cities on a date → ranked by weather quality score
compare_weather_region	Center city + radius km → grid sample → best spot in the area

Score factors: sunshine, temperature comfort (18–28°C sweet spot), precipitation, wind, UV.

Example prompts:

• "Moscow, Sochi, Kazan this Saturday — where's best?" → compare_weather_cities
• "Best weather within 300 km of Moscow next Sunday?" → compare_weather_region

Scheduled collection

Tool	Description
schedule_weather_job	Create a recurring data collection job (cron expression)
list_jobs	List jobs with schedule, status, and reading count
get_weather_summary	Aggregated stats (min/max/avg) over a time window
cancel_job	Stop and delete a job

Scheduled jobs survive server restarts — state is persisted in ~/.open-meteo-mcp/data.db.

Installation

git clone https://github.com/langepas/open-meteo-mcp.git
cd open-meteo-mcp
npm install
npm run build

Claude Desktop config

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "open-meteo": {
      "command": "node",
      "args": ["/absolute/path/to/open-meteo-mcp/dist/index.js"]
    }
  }
}

Restart Claude Desktop. Example prompts:

• "What's the weather in Moscow this week?" → geocode → get_forecast
• "Collect temperature in Saint Petersburg every hour" → schedule_weather_job
• "Show me the air quality summary for the last 24h" → get_weather_summary

Development

npm run build          # compile TypeScript
npm test               # run unit tests
npm run dev            # watch mode

Architecture

src/
├── index.ts           # McpServer + StdioServerTransport entry point
├── client.ts          # shared fetch helper (URLSearchParams, arrays → repeated keys)
├── db.ts              # SQLite (better-sqlite3): jobs + readings tables
├── scheduler.ts       # node-cron scheduler, restores jobs on start
└── tools/
    ├── forecast.ts    # get_forecast
    ├── archive.ts     # get_historical
    ├── air-quality.ts # get_air_quality
    ├── marine.ts      # get_marine
    ├── elevation.ts   # get_elevation
    ├── geocoding.ts   # geocode
    ├── flood.ts       # get_flood
    ├── ensemble.ts    # get_ensemble
    ├── climate.ts     # get_climate
    ├── seasonal.ts    # get_seasonal
    ├── dwd-icon.ts    # get_dwd_icon
    ├── ecmwf.ts       # get_ecmwf
    └── schedule.ts    # schedule_weather_job, list_jobs, get_weather_summary, cancel_job

License

MIT