Find current weather of any city using OpenWeatherMap API in Python

In this tutorial, we will retrieve the current weather of any city using the OpenWeatherMap API in Python. OpenWeatherMap provides a free weather API that allows up to 60 calls per minute without cost.

Prerequisites

Before getting started, you need to:

• Create a free account at OpenWeatherMap

• Generate your API key from the dashboard

• Install the requests module if not already available

Required Modules

We need two Python modules for this tutorial ?

• requests ? for making HTTP requests to the API

• json ? for parsing the JSON response (built-in module)

Step-by-Step Implementation

Follow these steps to fetch weather data ?

1. Import the required modules

2. Set up the base URL and API credentials

3. Construct the complete API URL

4. Make the HTTP request

5. Parse and display the weather information

Complete Example

Here's the complete implementation to get weather data for any city ?

import requests
import json

# Base URL for OpenWeatherMap API
BASE_URL = "https://api.openweathermap.org/data/2.5/weather?"

# City name and API key
CITY = "London"
API_KEY = "your_api_key_here"  # Replace with your actual API key

# Construct the complete URL
URL = BASE_URL + "q=" + CITY + "&appid=" + API_KEY

# Make HTTP request
response = requests.get(URL)

# Check if request was successful
if response.status_code == 200:
    # Parse JSON response
    data = response.json()
    
    # Extract main weather data
    main = data['main']
    temperature = main['temp']
    humidity = main['humidity']
    pressure = main['pressure']
    
    # Extract weather description
    weather_report = data['weather']
    
    # Display weather information
    print(f"{CITY:-^30}")
    print(f"Temperature: {temperature}K ({temperature - 273.15:.2f}°C)")
    print(f"Humidity: {humidity}%")
    print(f"Pressure: {pressure} hPa")
    print(f"Weather: {weather_report[0]['description'].title()}")
else:
    print(f"Error: Unable to fetch weather data (Status code: {response.status_code})")

The output of the above code is ?

-----------London------------
Temperature: 285.32K (12.17°C)
Humidity: 81%
Pressure: 1013 hPa
Weather: Few Clouds

Enhanced Version with Error Handling

Here's an improved version with better error handling and temperature conversion ?

import requests
import json

def get_weather(city_name, api_key):
    """Fetch weather data for a given city"""
    base_url = "https://api.openweathermap.org/data/2.5/weather?"
    complete_url = f"{base_url}q={city_name}&appid={api_key}"
    
    try:
        response = requests.get(complete_url, timeout=5)
        
        if response.status_code == 200:
            data = response.json()
            
            # Extract weather information
            main = data['main']
            weather = data['weather'][0]
            
            # Convert temperature from Kelvin to Celsius
            temp_celsius = main['temp'] - 273.15
            feels_like_celsius = main['feels_like'] - 273.15
            
            weather_info = {
                'city': data['name'],
                'country': data['sys']['country'],
                'temperature': round(temp_celsius, 1),
                'feels_like': round(feels_like_celsius, 1),
                'humidity': main['humidity'],
                'pressure': main['pressure'],
                'description': weather['description'].title(),
                'visibility': data.get('visibility', 'N/A')
            }
            
            return weather_info
            
        elif response.status_code == 404:
            return {"error": "City not found"}
        else:
            return {"error": f"API error: {response.status_code}"}
            
    except requests.exceptions.Timeout:
        return {"error": "Request timeout"}
    except requests.exceptions.RequestException as e:
        return {"error": f"Request failed: {str(e)}"}

# Usage example
city = "Paris"
api_key = "your_api_key_here"  # Replace with your actual API key

result = get_weather(city, api_key)

if 'error' in result:
    print(f"Error: {result['error']}")
else:
    print(f"\n{'='*40}")
    print(f"Weather in {result['city']}, {result['country']}")
    print(f"{'='*40}")
    print(f"Temperature: {result['temperature']}°C")
    print(f"Feels like: {result['feels_like']}°C")
    print(f"Humidity: {result['humidity']}%")
    print(f"Pressure: {result['pressure']} hPa")
    print(f"Description: {result['description']}")
    print(f"Visibility: {result['visibility']} meters")

Key Features

Common API Response Codes

• 200 ? Success, weather data retrieved

• 401 ? Invalid API key

• 404 ? City not found

• 429 ? API rate limit exceeded

Conclusion

The OpenWeatherMap API provides an easy way to fetch real-time weather data in Python. Always include proper error handling and consider converting temperature units for better user experience. Remember to keep your API key secure and never commit it to version control.