The first weather report from Mars, based on Viking probe data, was as follows: Light winds from the East in late afternoon changing to light winds from the southeast after midnight. Maximum winds were 15 miles per hour. Temperatures ranged from minus 122 degrees Fahrenheit just after dawn to minus 22 degrees Fahrenheit. . . Pressure steady at 7.70 millibars. (Earth's atmospheric pressure is over 1,000 millibars.)
Put simply, the weather on Mars is cold. In general, temperatures drop to -92┬║ F before dawn and rise by noon to a scorching -13┬║ F although some variations do occur. Because Mars is tilted on its axis it experiences seasonal changes like Earth. Most variations in high and low temperatures occur in the Martian winter.
Despite the regularity of low, low temperatures, however, the thin Martian atmosphere does produce a wide variety of weather including winds, clouds, low-level fogs, surface frost, cyclones and anti-cyclones (low and high pressure systems), and global dust storms.
Drastic climatic changes over the geologic timeline may explain why a planet that does not currently allow liquid water, shows evidences of running water in earlier eras.
