Based on the Köppen climate classification, Polychrome Mountain is located in a subarctic climate zone with long, cold, snowy winters, and mild summers. Temperatures can drop below −20 °C with wind chill factors below −30 °C. Precipitation runoff from the mountain drains into the Toklat River, which in turn is part of the Tanana River drainage basin. The months May through June offer the most favorable weather for climbing or viewing.