Aviation Weather

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?

Ask Claude...	What it does
"METAR EDDM"	Current weather at Munich airport
"TAF EDDF"	Forecast for Frankfurt
"Preflight briefing EDLI"	Full VFR brief: METAR + TAF + NWP forecast
"Route weather EDDM to LOWI"	Weather along a direct route (METARs + NWP + SIGMETs)
"Outlook for EDFE next week"	Per-day VFR go/no-go probability for the next 3–15 days
"Any PIREPs near EDDK?"	Recent pilot reports near Cologne
"SIGMETs over Germany"	Active significant weather warnings
"Hourly forecast for 48.14, 11.57"	ICON-D2 NWP model data for any coordinates

Data Sources

• aviationweather.gov — METARs, TAFs, PIREPs, SIGMETs (FAA/NOAA, worldwide)
• Open-Meteo — ICON-D2 / ICON-EU NWP forecasts (DWD models)
• Open-Meteo Ensemble — ensemble forecasts (ECMWF-ENS, GEFS) for the long-range outlook
• OurAirports — 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