If you are a frequent user of ‘Facebook Events’ then you will be happy to know that Facebook will start using the service ‘Weather Underground’ to forecast the conditions for the day your event is scheduled.
This comes after a small design update last Thursday when Facebook began using the weather prediction widget within various areas on both the mobile and desktop platforms. There are a few restrictions though, for Facebook to predict the weather for an event, the event must be no later than 10 days away. One nice addition is the weather widget showing up on public places (although right now it has only worked for one of my first 10 searches finally I saw it on the “Golden Gate Bridge”).
The events are most likely the only time you would use such a feature, you can still just type “Weather in San Francisco” into Google or Bing and be met with an instant answer, more data and a prettier interface.