The climate of Jordan is marked by sharp seasonal variations in both temperature and precipitation. Temperatures below freezing are not unknown in January, the coldest month, but the average winter temperature is above 7° C (45° F). In the Jordan Valley summer temperatures may reach 49° C (120° F) in August, the hottest month, but the average summer temperature in Amman is 26° C (78° F). Precipitation is confined largely to the winter season and ranges from about 660 mm (about 26 in) in the northwestern corner to less than 127 mm (less than 5 in) in the extreme east.