Taking into account the local weather in Siwa is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually July and August with an average temp of 86°F, while the coldest months are January and February with an average of 59°F. From January through March, the daytime average is 76°F and the nighttime average is 47°F. Between April and June, temperatures average 98°F during the day and 62°F at night. July through September averages 100°F during the day and 72°F at night. In October-December, the average temperature is 85°F during the day and 51°F at night.