Average temperatures in the desert at night is between 50 to 60 F during the warmer months but during the winter months it can be as high as 70 F during the daytime but when night comes around it can get below freezing.
So you'll have a nice warm day and then at night you'll be freezing.
The weather in a desert is very bipolar and in the summer the desert is very hot during the day and still cool at night.