Here’s a simple Python code snippet for finding the weather condition of any given city using Google’s Weather API. It’s also published on GitHub if you want to clone it.

import urllib2

def getWeather(city):

    #create google weather api url
    url = "http://www.google.com/ig/api?weather=" + urllib2.quote(city)

    try:
        # open google weather api url
        f = urllib2.urlopen(url)
    except:
        # if there was an error opening the url, return
        return "Error opening url"

    # read contents to a string
    s = f.read()

    # extract weather condition data from xml string
    weather = s.split("<current_conditions><condition data=\"")[-1].split("\"")[0]

    # if there was an error getting the condition, the city is invalid
    if weather == "<?xml version=":
        return "Invalid city"

    #return the weather condition
    return weather

def main():
    while True:
        city = raw_input("Give me a city: ")
        weather = getWeather(city)
        print(weather)

if __name__ == "__main__":
    main()

Update: GitHub is awesome because it allows very easy forking. Beau Martínez has made a fork of my script that includes Python 3 support, XML parsing instead of RegEx searching, and temperature reporting.