The northern and coastal regions of Israel have a Mediterranean climate with hot and dry summers and cool rainy winters. Whereas the southern and eastern areas of Israel are characterized by an arid climate, year-round. The rainy season goes from October to early May with rainfall peaking between December and February. You should note that rainfall varies considerably by regions from the North to the South. The highest rainfall is observed in the North and central parts of the country while in the southern part of Israel, rainfall is negligible.
The best time to visit Israel is in Spring before the heat becomes insupportable, or September and October when the heat starts to go down and temperatures become mild and pleasant.