All About Crete Weather. Weather in Kasteli. This detailed 10 Day Weather Forecast in Crete for Kasteli, Chania Prefecture is prepared for the local ex-pat residents and holidaymakers. Kasteli, also spelled as Kastelli is a quiet agricultural and coastal region with a pleasant climate. Kastelli has a rich heritage dating back to the Byzantine era through the magnificent churches that remain today. It is best to have a car to tour the lightly populated villages. Summer days can get very hot, so an early start is recommended. Before 9am is a good time when the temperature is still comfortable for driving around and you do not need to have the car's air conditioner turned on.