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Alex Spinov
Alex Spinov

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Build a Weather CLI Tool in 20 Lines of Python (Using a Free API)

#python #tutorial #beginners #discuss

I wanted a weather check in my terminal. No browser, no app, just type weather Berlin and get the answer.

20 lines of Python later, I had it.

The Complete Script 

import requests
import sys

def weather(city):
    url = f"https://api.open-meteo.com/v1/forecast"
    # First, geocode the city
    geo = requests.get(f"https://geocoding-api.open-meteo.com/v1/search?name={city}&count=1").json()

    if not geo.get('results'):
        print(f"City '{city}' not found")
        return

    lat = geo['results'][0]['latitude']
    lon = geo['results'][0]['longitude']
    name = geo['results'][0]['name']
    country = geo['results'][0].get('country', '')

    # Get weather
    w = requests.get(url, params={
        'latitude': lat, 'longitude': lon,
        'current_weather': True
    }).json()['current_weather']

    print(f"\n  {name}, {country}")
    print(f"  Temperature: {w['temperature']}C")
    print(f"  Wind: {w['windspeed']} km/h")
    print(f"  Direction: {w['winddirection']}")

if __name__ == '__main__':
    city = ' '.join(sys.argv[1:]) if len(sys.argv) > 1 else 'London'
    weather(city)
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Usage:

python weather.py Berlin
python weather.py "New York"
python weather.py Tokyo
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Output:

  Berlin, Germany
  Temperature: 12.3C
  Wind: 15.2 km/h
  Direction: 220
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Why Open-Meteo?

  • No API key required
  • No signup
  • No rate limit (within reason)
  • Global coverage
  • Free for non-commercial use

Compare this to OpenWeatherMap which requires an API key, or Weather.com which requires a paid subscription for decent access.

Add It as a Shell Alias 

# Add to .bashrc or .zshrc
alias weather='python3 /path/to/weather.py'
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Now just type weather Berlin from anywhere.

Extend It: 7-Day Forecast 

def forecast(city, days=7):
    geo = requests.get(f"https://geocoding-api.open-meteo.com/v1/search?name={city}&count=1").json()
    loc = geo['results'][0]

    w = requests.get('https://api.open-meteo.com/v1/forecast', params={
        'latitude': loc['latitude'],
        'longitude': loc['longitude'],
        'daily': 'temperature_2m_max,temperature_2m_min,precipitation_sum',
        'timezone': 'auto',
        'forecast_days': days
    }).json()

    print(f"\n  7-Day Forecast: {loc['name']}, {loc.get('country', '')}")
    print(f"  {'Date':12} {'High':>6} {'Low':>6} {'Rain':>8}")
    print(f"  {'-'*34}")

    for i in range(len(w['daily']['time'])):
        date = w['daily']['time'][i]
        high = w['daily']['temperature_2m_max'][i]
        low = w['daily']['temperature_2m_min'][i]
        rain = w['daily']['precipitation_sum'][i]
        print(f"  {date:12} {high:>5.1f}C {low:>5.1f}C {rain:>6.1f}mm")
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What CLI tools have you built?

Small Python scripts that solve daily annoyances are my favorite kind of coding. What is yours? Share in the comments — I am collecting ideas for a "developer CLI toolkit" article.

I write about Python, APIs, and developer tools. Follow for practical tutorials you can use today.

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Top comments (2)

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fluffyfi3 profile image
Ella •

Great work, Alex. I love how clean and smooth your code is, especially how you went about implementing geocoding for your city search (efaulting to London is a nice touch) and 7 day forecast functions. Also, I think using a no-key API, such as Open-Meteo, is a great tip for beginners. I completely agree that small projects that help us deal with our daily frustrations are probably the best way to practice.

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0012303 profile image
Alex Spinov •

Thank you — though the London default is the part I would take back.

It looks friendly and it is actually the same silent-failure shape I complain about everywhere else. Type "Munchen" instead of "München", get no geocoding hit, and the script cheerfully prints London's weather. No error, no warning, entirely plausible numbers. The honest version prints the resolved name and coordinates it actually used, and exits non-zero when the lookup comes back empty.

On Open-Meteo: agreed, and the reason is narrower than "it is free". Keyless means a beginner's first script has no signup, no billing page and no secret to leak into a screenshot. That removes the three things that usually kill a first project before it has run even once.