But don't confuse the permissiveness of San Fermin with the rest of the year. Any kind of disorderly behaviour is heavily frowned on in the bars and pubs. The permissiveness only lasts from the 6th of July to the 14th of July. Those ten days might give you the impression that Sodom and Gomorrah have been resurrected - but in fact, even in San Fermin, appearances are misleading. But summer storms can occur and when it rains it rains with a vengeance.
Temperatures can drop dramatically then and the days can be cool.
Maybe, between 10 and 15 degrees celsius. Other days can be extremely hot, up to 40 celsius. It depends on the year. Whatever the weather is like during the day, the nights are always a bit cool, particularly those dark hours just before dawn. And this is the time when many a reveller is inadvertantly parading from bar to bar in light dress oblivious to the change in temperature.