Here's the 9am AST Monday surface analysis from NWS Anchorage, showing a big high covering much of mainland Alaska. The coldest weather this afternoon is in the eastern Interior, where afternoon temperatures barely cracked 40 below. Sunday morning the cooperative station at Chicken reported the lowest official temperature thus far this event, 58 below.
The soundings from Fairbanks shows very little change in near surface temperatures between 3am and 3pm AST Monday. Temperatures at the higher elevation stations have approached 10 below today, while valleys have been stuck near 30 below.