Summer nights: Why does it never get cold in the deserts of the Southwest?

[BikeFreak]

Hi,

This is regarding at least the Sonoran desert which is located in the Western Part of Arizona. I biked in that area before during summer time and will likely do it again this year. It is common knowledge that the Sahara desert (Africa) gets ice cold each night, but why does it never cool down in the Sonoran desert? Probably the same in the Mojave desert. It can easily stay at 90 to 95 degF during the night which is really annoying when camping out. Can anyone link to some scientific explanation? :-)

Lucas

[bnolan@yahoo.com]

The factor that most detemines night time temperature drop is the water in the atmosphere above the desert.   With low enough humidity and no cloud cover, the earth surface can radiate heat directly to space.   The air over the Sahara is drier than in Arizona.

http://www.ucmp.berkeley.edu/exhibits/biomes/deserts.php

[sam21fire]

I'm guessing that you're mostly worried about summer months. In the winter it can get a**-chapping cold at night!

[kkway]

I once spent 5 weeks in the Mohave in July & August for military training. I can safely say it got cold every single night. I did not take my sleeping bag, as I was instructed to, but took 2 wool blankets and a poncho liner instead. I would fold each one in half, so 6 layers, and every single night I woke up freezing my tail off. It would not get cold enough to freeze water, but it would drop from a high of 118 to about 50 degrees by midnight.