Israel is small and climatically varied: the coast is Mediterranean, Jerusalem at 750 m is cooler and can snow, the Jordan valley and the Negev are desert, and Eilat is hot all year. The bigger planning factor is the calendar.
Spring, March to May
The best season. Temperatures of 20 to 27 degrees, wildflowers across the Galilee and the Negev in February and March, and the whole country walkable. Passover in March or April is a major domestic holiday when hotels fill and prices rise for a week.
Autumn, October and November
Equally good and often quieter, with warm sea and clear light. The September and October cluster of Rosh Hashanah, Yom Kippur and Sukkot is the busiest and most expensive period of the year domestically, and on Yom Kippur the entire country stops: no flights, no broadcasts, no traffic at all, and people walk and cycle on the empty motorways.
Summer, June to September
Hot and humid on the coast, 30 degrees with heavy air; dry and hotter inland; brutal at the Dead Sea and Eilat, above 40. Jerusalem is more bearable thanks to altitude and dry air. It is beach season, it is when Israelis take holidays, and it rains not at all between May and October.
Winter, December to February
Cool and wet on the coast at 10 to 18 degrees, colder in Jerusalem where snow falls every few years and closes the city when it does. The Negev and Eilat are pleasant, and this is when the south fills up. Flash floods in desert canyons follow winter rain and are lethal.
Shabbat
From sunset Friday to nightfall Saturday, public transport stops nationwide, most shops and many restaurants close, and Ben Gurion airport reduces operations. Tel Aviv, Haifa and Arab towns continue in part. Shared taxis, sherut, run when buses do not. Plan Friday shopping and Saturday activities accordingly.
Other calendars
Ramadan changes opening hours and creates a strong evening atmosphere in Jerusalem Old City, Nazareth and Akko. Christian Easter and Christmas fill Jerusalem, Bethlehem and Nazareth, in some years on two different dates.
The security situation
Conditions in the region change quickly and access to some areas is restricted or closed without notice. Check current advice from your own foreign ministry before booking and again before travelling, and register with your embassy where that is offered.