Mars is a pretty cold planet.
The average air temperature is –22°F (-30°C) in the day and –148°F (-100°C) at night.
Surface temperatures on Mars vary from lows of about -87 °C during the polar winters to highs of up to -5 °C during the summers.
The highest temperatures occur during the summer at the equator, but even then they hover around freezing.
The wide range in temperatures is due to the thin atmosphere which cannot store much heat from the Sun.
The low atmospheric pressure, and the low thermal inertia of the soil on Mars are also why there is a big temperature variance.
