From November to April, temperatures range in Cairo from 40° to 65°F, and during the hot period, May to October, from 70° to 110°F. The Mediterranean coast is usually 10° cooler, while Upper Egypt is 10° to 20° warmer. Extreme temperatures during both seasons are moderated by the prevailing northerly winds. The exception is the hot, dry southerly Khamaseen, named for the number 50 because it occurs in a 50-day timeframe from April to June. With winds up to 90 miles an hour, the resulting sandstorms close down airports and roads.