[2] Precipitation runoff from the peak drains into tributaries of the Fraser River.

[3] Most weather fronts originate in the Pacific Ocean, and travel east toward the Coast Mountains where they are forced upward by the range (Orographic lift), causing them to drop their moisture in the form of rain or snowfall.

As a result, the Coast Mountains experience high precipitation, especially during the winter months in the form of snowfall.

This climate supports the Place Glacier on the north slopes of Mount Oleg.

The months July through September offer the most favorable weather for climbing Mount Oleg.