[url]http://lifehacker.com/177700/add-weather-to-gcal[/url]

[quote][url=http://www.wunderground.com/]Weather Underground[/url] does exactly this. Just enter in your zipcode and at the top of the page (just below the banner ad and to the right) there's an iCal link that you can use.

After you've copied the iCal address from Weather Underground, go to your Google Calendar and click Settings -> Calendars -> Add Calendar -> Public Calendar Address. Paste your Weather Underground iCal address and voila, the week's weather forecast is automatically integrated in your calendar.[/quote]