Facebook started showing the weather on event pages:
How to switch temperature from Fahrenheit to Celsius? (or from Celsius to Fahrenheit)
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Sign up to join this communityFacebook started showing the weather on event pages:
How to switch temperature from Fahrenheit to Celsius? (or from Celsius to Fahrenheit)
Solution for October 2014 (if you don't see a "Today" dropdown as in the marked solution)
Go in the Settings page of Facebook:
https://www.facebook.com/settings
(OUTDATED see firepol's solution)
Go to your Events page
In the upper right, click the gear:
Switch to Celsius: