Why do temperatures change so sharply between day and night in the Sahara Desert?

The sharp temperature fluctuations between day and night in the Sahara Desert are primarily caused by the region's extreme aridity and lack of cloud cover.12

During the day, the absence of clouds allows high levels of solar radiation to reach the surface, causing temperatures to soar. Conversely, at night, that same lack of cloud cover—combined with very low atmospheric humidity—prevents the retention of heat. This allows the energy absorbed during the day to escape rapidly through long-wave radiation into the sky, leading to a dramatic drop in temperature.2

While daytime highs can exceed 100 °F (roughly 38 °C), nighttime lows in the northern Sahara can plummet as low as 25 °F (about –3.9 °C). This cycle of intense heating and rapid cooling is a defining characteristic of the desert's climate.12