Air Pressure
1-9 millibars (depending on altitude) or 600 Pa, average. This is 0.6% of Earth’s air pressure at sea level (14,7 psi or 101,3 kPa)

Note that in the southern winter, approximately 30% of the atmosphere’s carbon dioxide freezes out at the poles. (In the northern winter, about 12% freezes out.) Thus there is a strong seasonable component to the air pressure on Mars. The pressure ranges from about 1 bar to 0.7 bar over the course of the year (measured at the Viking lander sites). These values are lower at higher elevations.
If Mars had Earth’s surface gravity, the atmosphere would be held more tightly, and compressed into a smaller volume. Since Mars’ surface gravity is 38% of Earth’s, the atmosphere is ‘puffier’ and extends farther into space”
https://marspedia.org/Atmosphere

(The 1 bar to .7 bar must be a huge error. One bar is equal to earths atmosphere).

“”Mars’s atmosphere is so thin that it is more than a hundred times lighter than that on Earth. Atmospheric pressure at ground level is a fraction of ours, and about the same as it is 35 kilometres above the Earth. This thin atmosphere consists almost entirely of carbon dioxide with small fractions of nitrogen, argon, oxygen, and a few other gases. When the carbon dioxide condenses as ice at the poles every winter, the atmospheric pressure plummets by as much as 30%“”

Quote from the article in the link;
“The stratification of water vapour in Mars’s atmosphere, especially near the surface, is not well understood48, making the determination of the H2O frost point challenging due to its considerable variability; however, it is generally accepted that this point occurs at around 180 K.”

In other words, they are uncertain due to mitigating factors. But it is a good guess.
My guess is the Mars Version of earths stratospheric clouds from the solar wind are collecting in the caldera‘s cold spots?

Definition: A bar (symbol: bar) is a metric unit of pressure that is defined as exactly 100,000 pascals (symbol: Pa).

Mount Olympus caldera is 110pa. Close to vacuum. Water converts from a solid to a gas at six millibars. I’ve always wondered if a body is exposed to vacuum, will the heat in your body allow the water to boil and explode before you freeze solid?
Grandchildren have me distracted, need more coffee.

The idea that we could condense water from the atmosphere is great. I hope it’s true.