Based on the Köppen climate classification, Mount Custer has in a subarctic climate characterized by long, usually very cold winters, and short, cool to mild summers. Temperatures can drop below −10 °F with wind chill factors below −30 °F.
Mount Custer reflected in Cameron Lake
Geology
Like other mountains in Glacier National Park, Mount Custer is composed of sedimentary rock laid down during the Precambrian to Jurassic periods. Formed in shallow seas, this sedimentary rock was initially uplifted beginning 170 million years ago when the Lewis Overthrust fault pushed an enormous slab of precambrian rocks 3 mi (4.8 km) thick, 50 miles (80 km) wide and 160 miles (260 km) long over younger rock of the cretaceous period.
^Peel, M. C.; Finlayson, B. L. & McMahon, T. A. (2007). "Updated world map of the Köppen−Geiger climate classification". Hydrol. Earth Syst. Sci. 11: 1633–1644. ISSN1027-5606.
^Gadd, Ben (2008). "Geology of the Rocky Mountains and Columbias". {{cite journal}}: Cite journal requires |journal= (help)