Water ice precipitation is wide spread on Mars.
Notice also that the Hellas basin where some of the still existing glaciers were found is frequently a site of low lying clouds/fogs.
Martian Clouds.
...
"Fog
Fog often appears in low-lying areas. It typically occurs in the southern hemisphere especially in the Argyre and Hellas basins. It forms frequently in craters. Occasionally, it occurs in higher regions such as Sinus Sabaeus and Solis Planum."
http://www.solarviews.com/eng/marscld.htm#views
Bob Clark