Based on the Köppen climate classification, Mount Hayes 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. This climate supports glaciers on its slopes including the Hayes Glacier. Precipitation runoff from the mountain drains into tributaries of the Tanana River drainage basin. The months May through June offer the most favorable weather for climbing or viewing.