The dry season is from April till October and wind months as well. Temperature is tropical, no wetsuit needed. Water is 25-32°C. Air from 20-35°C. It is possible to surf all year around.
This beach is also very popular during the wet season for kite surfer, the wind is onshore therefore you have to start from the side of the bay. Most of the kitesurfer launch from the beach on the left of the Intercontinental Hotel but you must be very good in go upwind and there is fastidious shore break.
Just south if the airport. In town: you drive until the end of the road pass the fishing pier and you will find yourself very close to the airport. Park and then walk until where no more fishing boats are in the water. Here there is no shore break and the wind is more sideshore, you will be going out almost in front of the famous surf spot Airport Right.
04-03-11 jpk: just got back from bali , 2 weeks ago.
jimbaran dirty, on shore wind during all day, with coudy sky and rain, etc...
my advice forget about bali.