MCP YR.no Weather Server

A Model Context Protocol (MCP) server that provides access to Norwegian Meteorological Institute (YR.no) weather data. This server exposes weather forecasting capabilities through the MCP protocol, allowing AI assistants to fetch current weather, hourly forecasts, and daily forecasts for any location worldwide.

Features

• Current Weather: Get real-time weather conditions for any location
• Hourly Forecasts: Get detailed hourly weather predictions (up to 48 hours)
• Daily Forecasts: Get daily weather summaries (up to 7 days)
• Detailed Forecasts: Get comprehensive weather data with all available parameters
• Weather Descriptions: Convert weather symbol codes to human-readable descriptions

Installation

1. Clone this repository and navigate to the directory:

git clone <repository-url>
cd mcp-yrno-weather-prediction-server

2. Install dependencies:

npm install

3. Build the TypeScript code:

npm run build

Usage

Development Mode

Run the server in development mode with auto-reload:

npm run dev

Production Mode

Build and run the compiled server:

npm run build
npm start

MCP Tools

The server provides the following tools:

get_current_weather

Get current weather conditions for a location.

Parameters:

• latitude (number, required): Latitude coordinate (-90 to 90, max 4 decimals)
• longitude (number, required): Longitude coordinate (-180 to 180, max 4 decimals)
• altitude (number, optional): Altitude in meters

Example:

{
  "latitude": 59.9139,
  "longitude": 10.7522,
  "altitude": 100
}

get_hourly_forecast

Get hourly weather forecast for a location.

Parameters:

• latitude (number, required): Latitude coordinate (-90 to 90, max 4 decimals)
• longitude (number, required): Longitude coordinate (-180 to 180, max 4 decimals)
• hours (number, optional): Number of hours to forecast (1-48, default: 24)
• altitude (number, optional): Altitude in meters

get_daily_forecast

Get daily weather forecast for a location (up to 7 days).

Parameters:

• latitude (number, required): Latitude coordinate (-90 to 90, max 4 decimals)
• longitude (number, required): Longitude coordinate (-180 to 180, max 4 decimals)
• altitude (number, optional): Altitude in meters

get_detailed_forecast

Get detailed weather forecast with complete data available from the API.

Parameters:

• latitude (number, required): Latitude coordinate (-90 to 90, max 4 decimals)
• longitude (number, required): Longitude coordinate (-180 to 180, max 4 decimals)
• altitude (number, optional): Altitude in meters

get_weather_description

Convert weather symbol codes to human-readable descriptions.

Parameters:

• symbolCode (string, required): Weather symbol code (e.g., "clearsky_day", "rain", "snow")

Configuration

The weather client is configured with:

• User-Agent: "MCP-YrNo-Weather-Server/1.0 https://github.com/example/mcp-yrno-weather"
• Base URL: "https://api.met.no/weatherapi/locationforecast/2.0"
• Timeout: 10 seconds

You can modify the configuration in src/weather-client.ts if needed.

MCP Client Configuration

To use this server with an MCP client, add it to your client configuration:

{
  "mcpServers": {
    "yrno-weather": {
      "command": "node",
      "args": ["/path/to/your/mcp-yrno-weather-prediction-server/dist/index.js"]
    }
  }
}

API Rate Limits

The Norwegian Meteorological Institute API has rate limits:

• Be respectful with API usage
• The client automatically rounds coordinates to 4 decimals to comply with API requirements
• Handle rate limit errors (HTTP 429) gracefully

Weather Data

The server provides rich weather data including:

• Temperature (current, min, max)
• Humidity
• Air pressure
• Wind speed and direction
• Cloud coverage
• Precipitation amount and probability
• Weather condition symbols
• UV index (when available)

Error Handling

The server handles various error conditions:

• Invalid coordinates (HTTP 422)
• Rate limiting (HTTP 429)
• Access forbidden (HTTP 403)
• Network timeouts
• Invalid API responses

Development

Scripts

• npm run build: Compile TypeScript to JavaScript
• npm run dev: Run in development mode with tsx
• npm run watch: Run with file watching for development
• npm start: Run the compiled server

File Structure

src/
├── index.ts          # Main MCP server implementation
└── weather-client.ts # YR.no API client and types

License

MIT License

Credits

• Weather data provided by Norwegian Meteorological Institute
• Built with Model Context Protocol SDK