ESP32 OLED Weather Station with Real-Time Forecast

Build a sleek and modern weather station using an ESP32 board with a built-in 0.96″ OLED screen. This project fetches live weather data and 3-day forecasts from OpenWeatherMap and displays it in a stylish sliding UI, complete with icons, temperature, weather description, and date/time. It’s an ideal IoT project to demonstrate API integration, Wi-Fi networking, and display handling.

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Hardware Components

You’ll need the following hardware components to get started:

Component	Model / Type	Qty
ESP32 Board Thingspark	With built-in 0.96″ OLED (I2C)	1
Micro USB Cable	For programming and power	1
Wi-Fi Network	2.4GHz for ESP32 connection	1
Computer with Arduino IDE	IDE version 1.8.19 or later	1

Steps-by-Step Guide

(1) Setting up Arduino IDE

Download Arduino IDE Software from its official site. Here is a step-by-step guide on “How to install Arduino IDE“.

(2) ESP32 in Arduino IDE

There’s an add-on that allows you to program the ESP32 using the Arduino IDE. Here is a step-by-step guide on “How to Install ESP32 on Arduino IDE“.

(3) Register OpenWeathermap,get API key

Sign up OpenWeathermap new account: https://home.openweathermap.org/users/sign_up
Get OpenWeathermap API keys for “Project 1:Weather Station” https://home.openweathermap.org/api_keys

(4) Download Code File

Download the code files from the link given below. Locate “WeatherStation” Tab,
Replace the “********” in the WiFi_Name with your WiFi Name Replace the “********” in the WiFi_Password with your WiFi Password

Download Code

(4) Update OpenWeatherMap API Keys

Locate “WeatherStation” Tab, Replace the “******” in the OPEN_WEATHER_MAP_APP_ID with your
OpenWeathermap API keys which you registered in the previous preparations

(5) Wiring / Connections

ESP32 GPIO Pin	OLED Function	Note
GPIO 21 (D21)	SDA	I2C Data line
GPIO 22 (D22)	SCL	I2C Clock line
GND	GND	Ground connection
3.3V	VCC	Power supply for OLED

What the Code Does

Key Features:

Connects ESP32 to your Wi-Fi network
Uses NTP to get accurate date & time
Fetches current weather + 3-day forecast via OpenWeatherMap API
Displays:
- Temperature with icons (sun, cloud, rain, etc.)
- Weather description (e.g., “clear sky”)
- Day/date and time
Automatically updates every 20 minutes

How the UI Works:

Uses the OLEDDisplayUi library to create a sliding frame animation
Frames:
- Date & Time
- Current Weather
- 3-Day Forecast
Overlay at the bottom shows:
- Clock on the left
- Temperature on the right

Essential Code Behavior

WiFi connection:

WiFi.begin(WiFi_Name, WiFi_Password);

Time sync via NTP:

configTime(TZ_SEC, DST_SEC, "pool.ntp.org");

API requests (OpenWeatherMap):

currentWeatherClient.updateCurrentById(...);
forecastClient.updateForecastsById(...);

UI management:

ui.setFrames(frames, numberOfFrames);
ui.setOverlays(overlays, numberOfOverlays);
ui.init();

Weather update every 20 minutes:

if (millis() - timeSinceLastWUpdate > (1000L*UPDATE_INTERVAL_SECS)) {
  setReadyForWeatherUpdate();
}

This project is a beautiful blend of IoT, graphics, and real-time data. It’s perfect for a home dashboard, IoT showcase, or classroom demo to teach weather APIs and embedded displays.