ESP8266 WiFi Weather Dashboard You Can Open in Any Browser

Turn a NodeMCU and a DHT11 into a tiny web server: open its IP address on your phone and see live temperature and humidity from anywhere in the house.

What you’ll build

The ESP8266 NodeMCU connects to your WiFi and serves a small auto-refreshing web page. Every visit reads the DHT11 and returns the latest temperature and humidity — no cloud account, no app, just your local network.

Components you’ll need

Step-by-step guide

1. In the Arduino IDE add ESP8266 board support (Boards Manager → search “esp8266”), and select “NodeMCU 1.0”.
2. Wire the DHT11: VCC to 3V3, GND to GND, DATA to D4 (GPIO2).
3. Install the Adafruit DHT sensor library.
4. Put your WiFi name and password into the sketch and upload.
5. Open the Serial Monitor at 115200 baud — the ESP prints its IP address once connected.
6. Browse to that IP from any device on the same WiFi; the page refreshes itself every 5 seconds.

The code

A dozen lines of ESP8266WebServer code is all it takes to publish sensor data on your LAN.

#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <DHT.h>
DHT dht(2, DHT11);          // D4 = GPIO2
ESP8266WebServer server(80);
void handleRoot(){
  float t=dht.readTemperature(), h=dht.readHumidity();
  String html = "<meta http-equiv='refresh' content='5'>";
  html += "<h1>Arrowtron Weather</h1>";
  html += "<p>Temperature: " + String(t,1) + " &deg;C</p>";
  html += "<p>Humidity: " + String(h,0) + " %</p>";
  server.send(200, "text/html", html);
}
void setup(){
  Serial.begin(115200); dht.begin();
  WiFi.begin("YOUR_WIFI", "YOUR_PASSWORD");
  while(WiFi.status()!=WL_CONNECTED){ delay(500); Serial.print("."); }
  Serial.println(WiFi.localIP());
  server.on("/", handleRoot); server.begin();
}
void loop(){ server.handleClient(); }