get_weather_forecast

Retrieve 7-day weather forecasts for any global location using the Open-Meteo API, with Sydney as the default city. Specify city, country, and forecast duration (1-7 days) for accurate planning.

Instructions

Récupère les prévisions météo sur 7 jours (Sydney par défaut)

Input Schema

TableJSON Schema

Name	Required	Description	Default
`city`	No	Nom de la ville (optionnel, Sydney par défaut)	Sydney
`country`	No	Code pays optionnel
`days`	No	Nombre de jours de prévision (1-7)

Implementation Reference

src/index.js:240-290 (handler)

The primary handler function for the get_weather_forecast tool. It geocodes the city (using helper), fetches daily forecast data from Open-Meteo API, formats it into a structured text response with temperatures, conditions, wind, sunrise/sunset for each day.

async getWeatherForecast(city, country, days) {
  let location;
  
  if (city.toLowerCase() === 'sydney' && !country) {
    location = DEFAULT_LOCATION;
  } else {
    location = await this.getCoordinates(city, country);
  }

  const url = `${WEATHER_API}?latitude=${location.latitude}&longitude=${location.longitude}&daily=weather_code,temperature_2m_max,temperature_2m_min,apparent_temperature_max,apparent_temperature_min,sunrise,sunset,precipitation_sum,rain_sum,showers_sum,snowfall_sum,precipitation_hours,wind_speed_10m_max,wind_gusts_10m_max,wind_direction_10m_dominant&timezone=auto&forecast_days=${days}`;
  
  const response = await fetch(url);
  const data = await response.json();

  if (!response.ok) {
    throw new Error('Erreur lors de la récupération des prévisions');
  }

  const daily = data.daily;
  let forecastText = `🗓️ Prévisions météo ${days} jours pour ${location.name || location.admin1}${location.country ? `, ${location.country}` : ''}\n\n`;
  
  for (let i = 0; i < days; i++) {
    const date = new Date(daily.time[i]);
    const dayName = date.toLocaleDateString('fr-FR', { weekday: 'long' });
    const dateStr = date.toLocaleDateString('fr-FR');
    const weatherDesc = this.getWeatherDescription(daily.weather_code[i]);
    const windDir = this.getWindDirection(daily.wind_direction_10m_dominant[i]);
    
    forecastText += `📅 **${dayName.charAt(0).toUpperCase() + dayName.slice(1)} ${dateStr}**\n`;
    forecastText += `🌡️ ${Math.round(daily.temperature_2m_min[i])}°C → ${Math.round(daily.temperature_2m_max[i])}°C\n`;
    forecastText += `🤔 Ressenti: ${Math.round(daily.apparent_temperature_min[i])}°C → ${Math.round(daily.apparent_temperature_max[i])}°C\n`;
    forecastText += `☁️ ${weatherDesc}\n`;
    forecastText += `🌬️ Vent: ${Math.round(daily.wind_speed_10m_max[i])} km/h ${windDir}\n`;
    
    if (daily.precipitation_sum[i] > 0) {
      forecastText += `🌧️ Précipitations: ${daily.precipitation_sum[i]}mm\n`;
    }
    
    forecastText += `🌅 Lever: ${new Date(daily.sunrise[i]).toLocaleTimeString('fr-FR', {hour: '2-digit', minute: '2-digit'})}\n`;
    forecastText += `🌇 Coucher: ${new Date(daily.sunset[i]).toLocaleTimeString('fr-FR', {hour: '2-digit', minute: '2-digit'})}\n\n`;
  }

  return {
    content: [
      {
        type: 'text',
        text: forecastText.trim(),
      },
    ],
  };
}

src/index.js:70-95 (schema)

Tool schema definition in the ListTools response, specifying name, description, and input schema with optional parameters city, country, and days.

{
  name: 'get_weather_forecast',
  description: 'Récupère les prévisions météo sur 7 jours (Sydney par défaut)',
  inputSchema: {
    type: 'object',
    properties: {
      city: {
        type: 'string',
        description: 'Nom de la ville (optionnel, Sydney par défaut)',
        default: 'Sydney'
      },
      country: {
        type: 'string',
        description: 'Code pays optionnel',
      },
      days: {
        type: 'number',
        description: 'Nombre de jours de prévision (1-7)',
        default: 7,
        minimum: 1,
        maximum: 7
      }
    },
    required: [],
  },
},

src/index.js:149-150 (registration)
Registration in the CallToolRequestSchema switch statement that dispatches to the getWeatherForecast handler with default parameters.
```
case 'get_weather_forecast':
  return await this.getWeatherForecast(args.city || 'Sydney', args.country, args.days || 7);
```

src/index.js:178-190 (helper)

Helper function used by the handler to resolve city/country to latitude/longitude coordinates via Open-Meteo geocoding API.

async getCoordinates(city, country) {
  const query = country ? `${city}, ${country}` : city;
  const url = `${GEOCODING_API}?name=${encodeURIComponent(query)}&count=1&language=fr&format=json`;
  
  const response = await fetch(url);
  const data = await response.json();

  if (!response.ok || !data.results || data.results.length === 0) {
    throw new Error(`Ville "${query}" non trouvée`);
  }

  return data.results[0];
}

src/index.js:395-428 (helper)

Helper utility to translate weather codes to human-readable French descriptions, used in forecast formatting.

getWeatherDescription(code) {
  const descriptions = {
    0: 'Ciel dégagé',
    1: 'Principalement dégagé',
    2: 'Partiellement nuageux',
    3: 'Couvert',
    45: 'Brouillard',
    48: 'Brouillard givrant',
    51: 'Bruine légère',
    53: 'Bruine modérée',
    55: 'Bruine dense',
    56: 'Bruine verglaçante légère',
    57: 'Bruine verglaçante dense',
    61: 'Pluie légère',
    63: 'Pluie modérée',
    65: 'Pluie forte',
    66: 'Pluie verglaçante légère',
    67: 'Pluie verglaçante forte',
    71: 'Neige légère',
    73: 'Neige modérée',
    75: 'Neige forte',
    77: 'Grains de neige',
    80: 'Averses légères',
    81: 'Averses modérées',
    82: 'Averses violentes',
    85: 'Averses de neige légères',
    86: 'Averses de neige fortes',
    95: 'Orage',
    96: 'Orage avec grêle légère',
    99: 'Orage avec grêle forte'
  };
  
  return descriptions[code] || 'Conditions inconnues';
}

Weather MCP Server