Based on the Köppen climate classification, Mount Grosvenor is located in a subarctic climate zone with long, cold, snowy winters, and mild summers. Weather systems coming off the Gulf of Alaska are forced upwards by the Chugach Mountains (orographic lift), causing heavy precipitation in the form of rainfall and snowfall. Temperatures can drop below −20 °C with wind chill factors below −30 °C. This climate supports the Meares and Columbia Glaciers surrounding this mountain. The months May through June offer the most favorable weather for climbing or viewing.
Mt. Grosvenor (left) partially in clouds behind Meares Glacier
^Peel, M. C.; Finlayson, B. L.; McMahon, T. A. (2007). "Updated world map of the Köppen−Geiger climate classification". Hydrol. Earth Syst. Sci. 11. ISSN1027-5606.