Weather MCP Server

A free, production-ready Model Context Protocol (MCP) server for accessing weather data using the OpenWeatherMap API.

🌤️ Overview

This MCP server provides comprehensive weather information through a standardized interface, enabling AI assistants to access real-time weather data, forecasts, air quality information, and more.

✨ Features

🛠️ Tools (7 Available)

1. get_current_weather - Get current weather for any location
2. get_forecast - Get 5-day weather forecast with 3-hour intervals
3. search_location - Search for locations and get coordinates
4. get_weather_by_coordinates - Get weather by latitude/longitude
5. get_air_quality - Get air quality index and pollutant data
6. compare_weather - Compare weather across multiple cities
7. get_weather_alerts - Get severe weather alerts (note: requires paid tier)

📚 Resources (4 Available)

• weather://current - Current weather data
• weather://forecast - Weather forecasts
• weather://alerts - Weather alerts and warnings
• weather://history - Historical weather data

🚀 Quick Start

Prerequisites

1. Free API Key from OpenWeatherMap:

   • Sign up at https://openweathermap.org/api
   • Go to API keys section
   • Copy your API key (free tier includes 1000 calls/day)

2. Python 3.10+

Installation

cd weather-mcp-server
pip install -e .

Configuration

# Set your API key
export OPENWEATHER_API_KEY="your_api_key_here"

# Or create a .env file
echo "OPENWEATHER_API_KEY=your_api_key_here" > .env

Run the Server

python server.py

💡 Usage Examples

With Claude Desktop

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

{
  "mcpServers": {
    "weather": {
      "command": "python",
      "args": ["/full/path/to/weather-mcp-server/server.py"],
      "env": {
        "OPENWEATHER_API_KEY": "your_api_key_here"
      }
    }
  }
}

Then ask Claude:

• "What's the weather in Paris?"
• "Compare weather between New York, London, and Tokyo"
• "Give me a 5-day forecast for Seattle"
• "What's the air quality in Beijing?"

With Cursor IDE

Create .cursor/config.json:

{
  "mcp": {
    "servers": {
      "weather": {
        "command": "python",
        "args": ["server.py"],
        "cwd": "/full/path/to/weather-mcp-server",
        "env": {
          "OPENWEATHER_API_KEY": "your_api_key_here"
        }
      }
    }
  }
}

Programmatic Usage

from mcp.client import Client
import asyncio

async def main():
    async with Client() as client:
        await client.connect_stdio(
            command="python",
            args=["server.py"],
            env={"OPENWEATHER_API_KEY": "your_key"}
        )
        
        # Get current weather
        result = await client.call_tool(
            "get_current_weather",
            {"location": "London,UK", "units": "metric"}
        )
        print(result)
        
        # Get forecast
        forecast = await client.call_tool(
            "get_forecast",
            {"location": "New York,NY,US", "units": "imperial", "days": 3}
        )
        print(forecast)

asyncio.run(main())

🔧 Tool Details

get_current_weather

Get current weather conditions for a location.

Parameters:

• location (required): City name, e.g., "London,UK", "New York,NY,US"
• units (optional): "metric" (Celsius), "imperial" (Fahrenheit), or "standard" (Kelvin)

Returns:

{
  "location": {
    "name": "London",
    "country": "GB",
    "coordinates": {"latitude": 51.51, "longitude": -0.13}
  },
  "current": {
    "temperature": 15.5,
    "feels_like": 14.2,
    "humidity": 72,
    "description": "partly cloudy",
    "wind": {"speed": 5.2, "direction": 230},
    "pressure": 1013,
    "visibility": 10000
  },
  "sunrise": "2024-10-16T06:42:00",
  "sunset": "2024-10-16T18:15:00"
}

get_forecast

Get 5-day weather forecast with 3-hour intervals.

Parameters:

• location (required): City name
• units (optional): Temperature units
• days (optional): Number of days (1-5, default 5)

Returns:

{
  "location": {"name": "Paris", "country": "FR"},
  "forecast": [
    {
      "datetime": "2024-10-16T12:00:00",
      "temperature": 18.5,
      "description": "light rain",
      "humidity": 65,
      "pop": 0.3
    }
  ]
}

search_location

Search for a location and get its coordinates.

Parameters:

• query (required): Location name to search
• limit (optional): Max results (default 5)

Returns:

{
  "query": "Springfield",
  "results": [
    {
      "name": "Springfield",
      "country": "US",
      "state": "Illinois",
      "coordinates": {"latitude": 39.78, "longitude": -89.65}
    }
  ]
}

get_weather_by_coordinates

Get weather for specific coordinates.

Parameters:

• latitude (required): Latitude
• longitude (required): Longitude
• units (optional): Temperature units

get_air_quality

Get air quality index and pollutant levels.

Parameters:

• latitude (required): Latitude
• longitude (required): Longitude

Returns:

{
  "air_quality_index": 2,
  "aqi_level": "Fair",
  "components": {
    "co": 201.94,
    "no2": 13.56,
    "o3": 68.66,
    "pm2_5": 5.28,
    "pm10": 7.32
  }
}

compare_weather

Compare current weather across multiple cities.

Parameters:

• locations (required): Array of city names (2-5 cities)
• units (optional): Temperature units

Returns: Comparison of weather data for all locations.

📊 API Limits

Free Tier (OpenWeatherMap)

• Calls per day: 1,000
• Calls per minute: 60
• Features included:
  • Current weather
  • 5-day forecast
  • Geocoding
  • Air pollution data

Caching

The server automatically caches responses for 10 minutes to reduce API calls.

🌍 Supported Units

• metric: Temperature in Celsius, wind speed in m/s
• imperial: Temperature in Fahrenheit, wind speed in mph
• standard: Temperature in Kelvin, wind speed in m/s

🔐 Security

• API key stored in environment variable (never in code)
• HTTPS-only communication with OpenWeatherMap
• Input validation for all parameters
• Rate limiting awareness

🐛 Troubleshooting

"API key not configured" error

# Make sure you set the environment variable
export OPENWEATHER_API_KEY="your_key"

# Or check if it's set
echo $OPENWEATHER_API_KEY

"401 Unauthorized" error

• Verify your API key is correct
• Check if API key is activated (can take a few hours after signup)
• Ensure you're using the free tier correctly

Rate limit errors

The free tier allows 60 calls/minute and 1000/day. The server caches responses for 10 minutes to help avoid limits.

📚 Resources

• OpenWeatherMap API Docs: https://openweathermap.org/api
• Free API Signup: https://openweathermap.org/price
• MCP Specification: https://modelcontextprotocol.io
• OpenWeatherMap Weather Codes: https://openweathermap.org/weather-conditions

🧪 Testing

# Run tests
pytest tests/ -v

# Test specific tool
python -c "
import asyncio
from server import WeatherMCPServer

async def test():
    server = WeatherMCPServer()
    result = await server._get_current_weather({
        'location': 'London,UK',
        'units': 'metric'
    })
    print(result)

asyncio.run(test())
"

🎯 Example Queries

Ask your AI assistant:

1. Current Weather:

   • "What's the weather like in Tokyo?"
   • "Is it raining in Seattle right now?"
   • "What's the temperature in Miami?"

2. Forecasts:

   • "Give me a 3-day forecast for Paris"
   • "Will it rain in London this week?"
   • "What's the weather going to be like tomorrow in NYC?"

3. Comparisons:

   • "Compare the weather in Sydney, London, and New York"
   • "Which is warmer: Dubai or Bangkok?"

4. Air Quality:

   • "What's the air quality in Delhi?"
   • "Is the air quality good in Los Angeles?"

5. Location Search:

   • "Find all cities named Portland"
   • "Search for Springfield locations"

💻 Development

Project Structure

weather-mcp-server/
├── server.py           # Main server implementation
├── README.md          # This file
├── requirements.txt   # Python dependencies
├── pyproject.toml    # Package configuration
└── tests/            # Test suite
    └── test_server.py

Adding Custom Tools

# In server.py, add to list_tools():
Tool(
    name="your_custom_tool",
    description="Description",
    inputSchema={...}
)

# Add handler method:
async def _your_custom_tool(self, args):
    # Implementation
    pass

# Add to call_tool():
elif name == "your_custom_tool":
    result = await self._your_custom_tool(arguments)

📄 License

MIT License - Free to use, modify, and distribute

🤝 Contributing

Contributions welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Add tests
4. Submit a pull request

⭐ Features Coming Soon

• Historical weather data
• Weather maps
• UV index information
• Marine weather data
• Agricultural weather data

📞 Support

• Issues: GitHub Issues
• OpenWeatherMap Support: https://openweathermap.org/faq
• MCP Community: https://modelcontextprotocol.io

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