With around merely 40 rainy days a year on average, Israel is known for its sunny disposition, yet keep in mind this is a 4 season country. Summers are long, lasting from April to October and the height of heat and humidity is usually around July-August. Fall and winter last from November to March.
The southern city of Eilat enjoys nearly 360(!) sunny days a year, making it the hottest city in Israel (no pun intended).
The Israeli Meteorological Service: www.ims.gov.il
View FAQ at Tourist Information site
View tourist services at Tourist Information site