This is semi-arid, sub-arctic, taiga. If it didn't freeze up half the year it would be bone dry and dust, or loess even more obviously. It's been like this forever, even during the Ice Age, no glaciers but some ice in the shadows even in June. The wooly mammoths and sabertooth tigers are gone now, but they were kind of scrawny anyway.
In Fairbanks you get, what, about a 120 or 130 degree delta (highest summer high to lowest winter low) throughout the course of a typical year, once in a great while worse? Pretty extreme stuff!