How to Build a Weather Notifier App Using Python and a Public API

Whether you're a developer trying to stay dry or just looking for a fun Python project, a Weather Notifier App is a great choice. In this blog, we’ll build a simple weather notification tool using Python and the OpenWeatherMap API. You’ll learn about API integration, notifications, and simple scheduling — all in under 100 lines of code.

What You’ll Need:

• Python 3 installed

• requests library (for API calls)

• plyer library (for desktop notifications)

• A free API key from OpenWeatherMap

Step 1: Get an API Key from OpenWeatherMap

1. Visit https://openweathermap.org/api.

2. Sign up and log in.

3. Go to the "API keys" section in your account and generate a new key.

4. Use the “Current Weather Data” API.

Step 2: Install Required Libraries

Open your terminal and install the necessary Python libraries:
pip install requests plyer

Step 3: Fetch Weather Data Using Python

Create a new file called weather_notifier.py and start by writing a function to fetch weather data:

import requests

API_KEY = 'your_api_key_here'

CITY = 'London'

BASE_URL = "http://api.openweathermap.org/data/2.5/weather?"

def get_weather(city):
url = f"{BASE_URL}appid={API_KEY}&q={city}&units=metric"
response = requests.get(url)
data = response.json()

if data["cod"] != 200:
return f"Error: {data['message']}"

main = data["main"]
weather_desc = data["weather"][0]["description"]
temp = main["temp"]

return f"Weather in {city}:\n{weather_desc.capitalize()}, {temp}°C"

Step 4: Show the Notification

Now let’s display the weather using a desktop notification with the plyer library:

from plyer import notification

def notify_user(message):
notification.notify(
title="Weather Update",
message=message,
timeout=10 # seconds )

Step 5: Combine Everything

Put everything together in your main block:

if name == "main":
weather_report = get_weather(CITY)
notify_user(weather_report)

Now run the script:
python weather_notifier.py
You’ll see a system notification pop up with the current weather.

Optional: Add Automatic Scheduling

If you want the app to check the weather every few hours, install the schedule library:
pip install schedule
Then add this to your script:

import schedule
import time

schedule.every(3).hours.do(lambda: notify_user(get_weather(CITY)))

while True: schedule.run_pending()
time.sleep(1)

Bonus Ideas:

• Add a GUI using Tkinter or PyQt

• Fetch weather for multiple cities

• Use geolocation to get weather automatically

• Send weather via email or SMS using Twilio or SMTP

Conclusion:

You’ve just built a simple, useful Weather Notifier App in Python using real-time data from OpenWeatherMap. This project is a great introduction to working with APIs and automation in Python. It's easily extendable and can be personalized in countless ways.

Now you’ll never be caught without an umbrella again!