OpenWeatherMap Arduino Library

🎯 Features

🔧 Supported Boards

📦 Installation

Arduino Library Manager (Recommended)

Manual Installation

PlatformIO

lib_deps =
 https://github.com/coloz/OpenWeatherMap-library.git
 bblanchon/ArduinoJson@^7.0.0

🔑 Getting an API Key

📖 Quick Start

#include <OpenWeatherMap.h>
// Your credentials
const char* WIFI_SSID = "your_wifi_ssid";
const char* WIFI_PASSWORD = "your_wifi_password";
const char* API_KEY = "your_openweathermap_api_key";
OpenWeatherMap weather;
void setup() {
 Serial.begin(115200);
 
 // Connect to WiFi
 WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
 while (WiFi.status() != WL_CONNECTED) {
 delay(500);
 }
 
 // Initialize library
 weather.begin(API_KEY);
 weather.setUnits(OWM_UNITS_METRIC); // Celsius
 weather.setLanguage("en");
 
 // Get current weather
 OWM_CurrentWeather data;
 if (weather.getCurrentWeather(31.23f, 121.47f, &data)) {
 Serial.print("Temperature: ");
 Serial.print(data.main.temp);
 Serial.println("°C");
 }
}
void loop() {
 // Your code here
}

📚 API Reference

Initialization

OpenWeatherMap weather;
weather.begin("YOUR_API_KEY");
weather.setUnits(OWM_UNITS_METRIC); // OWM_UNITS_STANDARD, OWM_UNITS_METRIC, OWM_UNITS_IMPERIAL
weather.setLanguage("en"); // Language code (e.g., "en", "zh_cn", "de")
weather.setTimeout(5000); // HTTP request timeout in milliseconds (default: 5000)
weather.setDebug(true); // Enable debug output

Current Weather

OWM_CurrentWeather data;
// By coordinates
weather.getCurrentWeather(latitude, longitude, &data);
// By city name
weather.getCurrentWeatherByCity("London", "GB", &data);
// Access data
Serial.println(data.main.temp); // Temperature
Serial.println(data.main.humidity); // Humidity %
Serial.println(data.weather.description); // "clear sky", etc.
Serial.println(data.wind.speed); // Wind speed

5-Day Forecast

OWM_Forecast forecast;
// Get all forecasts (up to 40 items)
weather.getForecast(latitude, longitude, &forecast);
// Get limited forecasts
weather.getForecast(latitude, longitude, &forecast, 8); // 24 hours
// By city name
weather.getForecastByCity("Tokyo", "JP", &forecast);
// Access data
for (int i = 0; i < forecast.cnt; i++) {
 Serial.print(forecast.items[i].dt_txt);
 Serial.print(": ");
 Serial.print(forecast.items[i].main.temp);
 Serial.println("°C");
}

Air Pollution

OWM_AirPollution pollution;
// Current air pollution
weather.getAirPollution(latitude, longitude, &pollution);
// Air pollution forecast
OWM_AirPollution forecast[24];
int count = weather.getAirPollutionForecast(lat, lon, forecast, 24);
// Historical data
int count = weather.getAirPollutionHistory(lat, lon, startTime, endTime, history, 100);
// Access data
Serial.println(pollution.aqi); // Air Quality Index (1-5)
Serial.println(pollution.components.pm2_5); // PM2.5
Serial.println(pollution.components.pm10); // PM10
Serial.println(OpenWeatherMap::getAQIDescription(pollution.aqi));

Geocoding

OWM_GeoLocation locations[5];
// City name to coordinates
int count = weather.getCoordinatesByName("Paris", "FR", NULL, locations, 5);
// ZIP code to coordinates
OWM_GeoLocation loc;
weather.getCoordinatesByZip("10001", "US", &loc);
// Coordinates to location name (reverse geocoding)
count = weather.getLocationByCoordinates(48.8566f, 2.3522f, locations, 5);
// Access data
Serial.println(locations[0].name);
Serial.println(locations[0].lat);
Serial.println(locations[0].lon);

📊 Data Structures

OWM_CurrentWeather

OWM_AirPollution

Air Quality Index Levels

🌐 Supported Languages

📝 Examples

⚠️ Troubleshooting

Connection Issues

Memory Issues

API Rate Limits

📄 License

🙏 Acknowledgments

📮 Support