A bit of an exaggeration
The martian atmosphere is, on average, about 10,000 times drier than the atmosphere of earth. And water vapor in the atmosphere doesn't equate to the surface being wet - and certainly not "wetter" than Antarctica. As for "locations near the equator on Mars that are far above the 10 micron level," that is speculation on your part. But once again, water vapor in the atmosphere doesn't mean that the surface of Mars is also wet.
The bottom line is that it doesn't rain on Mars. Perhaps there is a rare light snowfall. And we know that exceptionally thin films of water frost will precipitate to the surface in the winter. But to proclaim that Mars is "actually wetter than Antartica" is a grossly deceptive statement.