The Sunday morning sounding shows the sharp surface based inversion, but the warmest air is way up there, above 1600 meters AGL.
Sunday mid-morning temperatures:
Caribou Peak: +4F
Cleary Summit: +2F
Angel Creek RAWS +1F
Fairbanks International: -27F
Eielson AFB -30F
Woodsmoke near North Pole: -33F
Of course, Angel Creek is not a "hill" location. But it is a breezy location.