November weather
If you’re visiting Ibiza in November you will probably not want to use your bikini. Maybe you can get some great days with temperatures in the early 20s (celsius) in the beginning of the month, but the weather is declining and Ibiza is putting on its’ winter dress.

Most shops are closed in November.
Days will be fine and you may get to use your t-shirt, but remember to bring a jacket and a sweater for the nights.
November
Average high °C (°F): 18 (64)
Daily mean °C (°F): 15 (59)
Average low °C (°F): 12 (54)
Rainy days: 9