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