Saudi Arabia has a desert climate with extreme heat during the day, a big drop in temperature at night, and a low annual rainfall in the region. The average summer temperature is 45 degrees Celsius while in the winter the temperature rarely drops under 0 degrees Celsius. In spring and autumn temperatures are more moderate averaging around 29 degrees Celsius. Rainfall in the area is very low throughout the year as well as being erratic. The year's rainfall may just occur in one or two local thunderstorms.
-- Average temperature graph
There are three climatic zones in Saudi Arabia; first desert is almost everywhere, second steppe is along the western highlands, forming a strip less than 100 miles wide in the north but becoming almost 300 miles wide at Mecca, and third a small area of humid and mild temperature conditions, with long summers, in the highlands just north of Yemen.
To the left is a climatogram of Algeria which has a tropical desert climate like that of Saudi Arabia.