Tech With Galvan

Introduction

In this project you will build a real-time weather app using Python, Streamlit, and the free OpenWeatherMap API. Type any city name and instantly see the current temperature, humidity, wind speed, and weather description.

Prerequisites

Python 3.8+ — python.org

Libraries — Install with pip:

code

pip install streamlit requests

OpenWeatherMap API Key — Sign up free at openweathermap.org and copy your key from the dashboard.

Step 1: Create the Script

Create weather_app.py and paste the following:

code

import streamlit as st
import requests

st.set_page_config(page_title="Weather App", page_icon="🌤️")
st.title("🌤️ Real-Time Weather App")

API_KEY = "YOUR_OPENWEATHERMAP_API_KEY"

city = st.text_input("Enter a city name:", placeholder="e.g. Mumbai, London, New York")

def get_weather(city):
    url = f"https://api.openweathermap.org/data/2.5/weather?q={city}&appid={API_KEY}&units=metric"
    return requests.get(url).json()

if st.button("Get Weather") and city:
    data = get_weather(city)
    if data.get("cod") == 200:
        col1, col2 = st.columns(2)
        with col1:
            st.metric("🌡️ Temperature", f"{data['main']['temp']} °C")
            st.metric("💧 Humidity", f"{data['main']['humidity']}%")
        with col2:
            st.metric("💨 Wind Speed", f"{data['wind']['speed']} m/s")
            st.metric("☁️ Condition", data['weather'][0]['description'].title())
        st.success(f"Showing weather for **{data['name']}, {data['sys']['country']}**")
    else:
        st.error("City not found. Please check the spelling and try again.")

Step 2: Add Your API Key

Replace YOUR_OPENWEATHERMAP_API_KEY with the key you copied from the OpenWeatherMap dashboard.

Step 3: Run the App

code

streamlit run weather_app.py

Step 4: Use the App

Type a city name and click Get Weather. The app displays current conditions in a clean two-column layout with metric cards.

Key Concepts

`requests.get()` — Sends the HTTP GET request to the OpenWeatherMap API.

`response.json()` — Parses the JSON response into a Python dictionary.

`st.metric()` — Renders each weather value as a styled metric card.

`st.columns()` — Splits the layout into two side-by-side columns.

What to Try Next

Show a 5-day forecast using the /forecast endpoint.

Add weather icons from OpenWeatherMap's icon library.

Allow users to switch between Celsius and Fahrenheit using a toggle.