Step-by-Step Guide to DIY ESP32 Weather Station

#include 
#include 
#include 
#include 

// — CONFIGURATION —
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for SSD1306 display connected via I2C (SDA, SCL)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

#define DHTPIN 4          // Digital pin connected to DHT sensor
#define DHTTYPE DHT11     // Uncomment for DHT11, use DHT22 for DHT22/AM2302

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(115200);

  // Initialize DHT sensor
  dht.begin();

  // Initialize OLED display
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }

  display.clearDisplay();
  display.setTextColor(WHITE);
  display.setTextSize(1);
  display.setCursor(0, 10);
  display.println("Weather Station");
  display.println("Initializing...");
  display.display();
  delay(2000);
}

void loop() {
  // Wait 2 seconds between measurements
  delay(2000);

  // Read humidity and temperature
  float h = dht.readHumidity();
  float t = dht.readTemperature();

  // Validate readings
  if (isnan(h) || isnan(t)) {
    Serial.println(F("Failed to read from DHT sensor!"));
    return;
  }

  // Print to Serial Monitor
  Serial.print(F("Humidity: "));
  Serial.print(h);
  Serial.print(F("%  Temperature: "));
  Serial.print(t);
  Serial.println(F("°C"));

  // Display on OLED
  display.clearDisplay();
  
  display.setTextSize(1);
  display.setCursor(0, 0);
  display.println("Room Condition:");

  display.setTextSize(2);
  display.setCursor(0, 15);
  display.print("T: ");
  display.print(t);
  display.println("C");

  display.setCursor(0, 40);
  display.print("H: ");
  display.print(h);
  display.println("%");

  display.display();
}

Once your weather station is working, there are plenty of ways to expand it:

• Send data to your phone using MQTT or HTTP.
• Upload readings to the cloud for remote monitoring.
• Add additional sensors—rain, light, air pressure, or any other environmental measurement.
• Run on batteries or a solar panel for a standalone setup.

With the ESP32 and modular sensors, your weather station can scale as much as your creativity allows.