The temperature dropped to 28 °F this morning at the Fairbanks airport, marking the first freeze of the season. As I mentioned last week, the first freeze at the airport typically waits until the 850 mb temperature is a few degrees below freezing, especially when it's early in the autumn. Last week the 850 mb temperature dropped to -2.7 °C, but it was still August and no freeze occurred; but yesterday the 850 mb temperature was measured at -4.7 °C above Fairbanks.
Today's frost was one week earlier than normal and the earliest at the airport since 2005; but 28 °F or lower is not typically observed until September 23 (1981-2010 median), so in that respect we're nearly three weeks ahead of schedule.
In more rural areas of the interior much cooler temperatures were observed this morning, including:
Norutak Lake RAWS in Kobuk National Preserve 14 F
Circle Hot Springs 15 F
Chicken 17 F
Eagle airport 18 F
Goldstream Creek 19 F
Bettles 21 F
Tanana 22 F