Book 7, Question 67
Why Do Deserts Get Hot Days and Cold Nights?
Deserts can be scorching hot during the day and surprisingly cold at night. Dry air and clear skies let heat escape into space after sunset. So the temperature can swing by 20 degrees Celsius or more in a single day.
More fun facts
- Desert daytime temperatures average about 38 degrees Celsius (100 degrees Fahrenheit), and nights can drop below freezing.
- In the midday sun, the ground can get much hotter than the air. Scientists measured soil at 71.5 degrees Celsius while the air above was 42.5 degrees.
- Not every desert night is cold. In Death Valley, summer nights may only cool to 85 to 95 degrees Fahrenheit.
- The world's highest recorded air temperature, 134 degrees Fahrenheit, was measured in Death Valley on July 10, 1913.
- Death Valley gets less than 2 inches of rain a year on average.
- Weather thermometers are kept 1.2 to 2 meters above the ground and shaded from direct sun, so they measure the air, not the hot ground.
Sources: NASA Science, NASA Science, National Park Service
Questions kids ask
What is the hottest temperature ever recorded?
134 degrees Fahrenheit, in Death Valley, California, on July 10, 1913.
Is sand hotter than the air?
Yes. In the midday sun, the ground can be much hotter than the air above it.