For you determined clubbers, it's the month of the closing parties, and as such should not be missed. Weatherwise, you'll get some rain, which tends to come down in great lumps. On the rare occasions Ibiza does gets rained upon, there is absolutely nothing subtle about it. That said, October is on the whole a mild month, though you might want to bring a jumper, wrap or jacket for the evenings and nights, which can get chilly.
What to do in October: Fiesta de la Mare de Deu Del Pilar de La Moia. Quite a mouthful, eh? Usually held on the 12th.
Average temperatures: max 24ºC, min 13ºC
Average sunlight hours: 10
12th October - Fiesta de la Mare de Deu Del Pilar de La Moia
15th October - Es Cubells
24th October - San Rafael
Weather over the months on Ibiza