Based on the Köppen climate classification, Mount Macpherson is located in a subarctic climate zone with cold, snowy winters, and mild summers.[5] Winter temperatures can drop below −20 °C with wind chill factors below −30 °C. Despite the modest elevation, the climate supports a small pocket glacier on the northeast face. Precipitation runoff from Mount Macpherson drains north into tributaries of the Columbia River.
^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.