The pressure is very low on mars. If you were to step out of your space suit your blood would literally boil. In winter the climate can get as low 92º Fahrenheit. The average temp on mars -80ºF. The atmospheres very thin and the ice caps it can get up to negative 252º. As I was saying the atmosphere is very thin it is 100 times thinner then earths. At times it even snows but it is not like earths snow it is carbon dioxide. There is lots of dust storms on mars and in the storms there is rust and if you breathed that in you would die almost immediately. Several studies have shown that there is abandonment water ice under the surface. Also there may be life under ground mars along with flowing water.