Yes, although we the audience don't actually see it happen.
In the short story Master and Apprentice (from the anthology From a Certain Point of View), Obi-Wan describes the desert thusly;
Some believe the desert to be barren. This proves only that they do
not know the desert.
Deep within the dunes dwell small insects that weave nets to trap one
another, and burrowing snakes with scales the color of stones so that
no hunter can find them. Seeds and spores from long-dead plants lie
dormant in the warmth, waiting for the rainfall that comes once a
year, or decade, or century, when they will burst into verdant life as
brief as it is glorious. The heat of the suns sinks into the grains of
sand until they glow, containing all the energy and possibility to
become glass the color of jewels. All of these sing individual notes
in the one great song of the Whills.
Additionally, we see that there are dense clouds that form in the atmosphere. Cumulus clouds would generally imply periodic rainfall.
And we also learn from the Complete Location factbook that Tatooine does have some surface water, albeit scant. Again, this would generally imply replenishment.
Surface Water: 1%
... Fossils bear testament to an ocean-covered formative period, although today Tatooine is all but waterless.