Mars doesn't really experience rain as we know it on Earth. While there is a small amount of water vapor in the Martian atmosphere, the atmospheric pressure is so low that liquid water cannot exist on the surface for very long.

Here's what we know:

* Trace Amounts: There is some evidence of very occasional light snowfall at the poles.

* Sublimation: Instead of rain, water vapor in the Martian atmosphere typically sublimates directly into ice.

* Past Rain: There is strong evidence that Mars once had a much thicker atmosphere and liquid water on its surface, possibly even oceans.

So, while Mars might see a few snowflakes every now and then, it's not a planet where you'd need an umbrella!