Bullfights are rain or shine.
The only way a fight would be cancelled is if the rain is hard and continuous.
If this happens, anyone having purchased tickets for that day will be able to get a refund of their ticket price by submitting them to the Teyci kiosk.
This is only done if the cancellation happens before the fight begins, however, if the fight is cancelled after it has begun, no refund can be given.
This is a good reason to check the weather forecast when choosing your attendance dates.
In the 2014 season, none of the bullfights were cancelled out of more than 100 celebrations.