There is a rover on Mars that still measures the air every single sol. These are its numbers, not an estimate.
The air on Mars is less than one percent of Earth's. Thin air holds almost no heat, so the ground warms quickly in sunlight and loses everything again after dark. A single day can swing more than sixty degrees.
Ground temperature swings even harder than air temperature, because the surface itself is what the sun heats. That is why the two rows above rarely match.
Pressure rises and falls once every Mars year, as carbon dioxide freezes onto the polar caps in winter and returns to the atmosphere in summer. About a quarter of the whole atmosphere takes part in that cycle.
| Average temperature | about -63 °C over the whole planet |
|---|---|
| Warmest recorded | about +20 °C, near the equator at midday in summer |
| Coldest recorded | about -140 °C, at the winter pole |
| Atmospheric pressure | about 600 to 1,000 Pa, roughly 0.6 % of Earth's |
| Length of a day | 24 hours 39 minutes 35 seconds (one sol) |
| Length of a year | 687 Earth days |
Two places at the same latitude can be a different temperature at night, and the reason is what the ground is made of. Rock and bedrock hold the day's heat and cool slowly. Dust and sand let it go almost at once.
Mars Odyssey has been recording that difference in the infrared since 2001. On the KUON MARS map you can switch that layer on and see it: the bright places are rock, the dark places are dust.
It is not a temperature reading — the published mosaic is a visual representation only — but it tells you something the elevation map cannot.