Sudan lies within the tropics. Its climate is primarily dictated by the dry northeasterly trade winds from the Arabian Peninsula and the moist southwesterly monsoon winds from the Congo river basin, which shift northwards in a seasonal pattern, bringing the typical summer rains up to the latitude of the Great Nile Bend. The regions to the north are virtually without precipitation. The Libyan and the Nubian Desert in northern Sudan are among the driest and sunniest places on earth.
As part of the tropics, Sudan has a hot climate throughout the year. Temperatures are highest in May and June i.e. at the end of the dry season, when they can reach up to 48 °C. The coolest time is December to January with around 25 °C during the day. Particularly in the desert, temperatures may drop sharply at night, the difference being sometimes up to 20 °C. Occasional sandstorms are a fascinating phenomenon to witness.
As everywhere else on the planet, also in Sudan the weather has become more unpredictable in recent years. Even in winter it may be quite hot but nights, particularly in December and January, may also be very cold.