The interior intermontane plateau receive about 400 mm of annual precipitation, much less than the 1000 to 1500 mm levels in the eastern mountains, and the even higher levels in the western mountains. Snowfall accounts for 35 to 60% of all precipitation. Winters are long and cold, with January mean temperatures between -15 °C and -27 °C. Summers are warm but short, with July mean temperatures between 12 °C and 15 °C.
