Imagine that you will be visiting the Southern Hemisphere of Mars during its summer. What are some of the atmospheric conditions you might encounter?
Marginal differences between the seasons.
Mars' atmosphere is at most 1% of that of the earth. It also only gets about 44% as much sunlight as earth. Therefor, the daylight hours can see temperatures as high as 20 degrees C and during the night it can plummet to -100 degrees C. The reason for these great swings in temperature are directly related to Mars' extremely thin atmosphere.