Guallatiri has glaciers, including one on the summit and an ice cap above elevation. It is the most southern volcano in the Central Andes with an ice cap as south of Guallatiri tropical summer precipitation is insufficient to support glaciation; only south of 27° does winter precipitation become sufficient to support glaciers again. Fumaroles have melted holes in the glaciers. Thin moraines are preserved on the flanks at altitudes of .