Aviation Weather MCP Server

Aviation weather briefings directly in Claude. METARs, TAFs, PIREPs, SIGMETs, and ICON-D2 NWP forecasts — no API key required.

Just ask Claude things like:

• "METAR EDDM"
• "Preflight briefing EDLI"
• "Route weather EDDM to LOWI"
• "Any SIGMETs over Germany?"

Prerequisites

You need two things installed:

1. Claude Desktop — download from https://claude.ai/download
2. Node.js — download from https://nodejs.org (pick the LTS version). Use a

patched release: 22.23.4+, 24.22.1+, or 26.12.1+. These carry the October 2026 security fixes (including a Brotli-decoder RCE reachable through fetch); older builds and the end-of-life Node 20 are vulnerable. The server prints a warning on startup if it detects an unpatched Node.

To check if Node.js is already installed, open Terminal (Mac) or Command Prompt (Windows) and type:

node --version

If you see a version at or above v22.23.4 (or v24.22.1 / v26.12.1), you're good to go. If it's lower, update Node from https://nodejs.org.

Setup (3 minutes)

Step 1: Open the Claude Desktop config

1. Open Claude Desktop
2. Click the gear icon (top right) to open Settings
3. Go to Developer
4. Click Edit Config

This opens a JSON file in your text editor.

Step 2: Add the weather server

If the file is empty or just has {}, replace it with:

{
  "mcpServers": {
    "aviation-weather": {
      "command": "npx",
      "args": ["-y", "aviation-weather-mcp"]
    }
  }
}

If the file already has content (e.g. other MCP servers), add the "aviation-weather" block inside the existing "mcpServers" section.

Step 3: Restart Claude Desktop

Quit Claude Desktop completely and reopen it. The first start may take 10-15 seconds longer while it downloads the weather server.

Step 4: Test it

Start a new chat and ask: "METAR EDDF"

Claude should respond with the current weather at Frankfurt airport. If it works, you're all set!

What can it do?

Data Sources

• [aviationweather.gov](https://aviationweather.gov) — METARs, TAFs, PIREPs, SIGMETs (FAA/NOAA, worldwide)
• [Open-Meteo](https://open-meteo.com) — ICON-D2 / ICON-EU NWP forecasts (DWD models)
• [Open-Meteo Ensemble](https://open-meteo.com/en/docs/ensemble-api) — ensemble forecasts (ECMWF-ENS, GEFS) for the long-range outlook
• [OurAirports](https://ourairports.com) — bundled offline ICAO → coordinates database (~22k airports, incl. GA fields), Public Domain

Notes

• Works worldwide for METARs, TAFs, PIREPs, and SIGMETs
• ICON-D2 high-resolution forecasts (2km) cover Central Europe (43-58°N / 4-21°E, 48h horizon)
• Outside Central Europe, it falls back to ICON-EU (7km resolution, 120h horizon)
• ICAO codes are resolved automatically — just use the 4-letter code. Resolution works offline from a bundled airport database, so even pure GA fields without a METAR (e.g. EDVY) work; you can also pass lat/lon directly
• Visibility is reported in km
• Open-Meteo serves no usable cloud base, so the hourly NWP forecasts (wx_icon_d2, wx_preflight, wx_route) derive a cloud ceiling from pressure-level cloud cover (lowest broken/overcast deck ≥50%, in ft AGL). The output always states it explicitly — ceil ~1700ft, ceil none<8600ft (no deck below), or ceil n/a (no data) — so a missing ceiling never looks like clear skies
• The 3–15 day outlook is a coarse confidence measure (share of ensemble members with poor VFR conditions), not a precise forecast. It uses low-cloud cover as the VFR proxy (Open-Meteo serves no usable cloud base) and shows the ECMWF-IFS trend plus an ICON-EU cross-check for the first ~5 days

Usage with Claude Code

claude mcp add aviation-weather -- npx -y aviation-weather-mcp

Troubleshooting

Claude doesn't show weather tools: Make sure you restarted Claude Desktop after editing the config. Check that the JSON syntax is valid (no trailing commas, matching brackets).

"npx: command not found": Node.js is not installed or not in your PATH. Download it from https://nodejs.org.

Slow first start: The first time, npx downloads the package (~30KB). After that it's cached and starts instantly.

Disclaimer

This tool is for informational purposes only and is not a replacement for an official pre-flight weather briefing. Always use approved weather services and follow your national aviation authority's requirements for flight preparation.

License

MIT