Here's this afternoon's scene on the Chena River in Fairbanks, where the temperature dropped to +3°F this morning. This is the coldest it's been this early in the season since 2012; but in 1965 the mercury dropped to -15°F on October 20 (and the high was only +3°F on the 21st!)
Sub-zero temperatures were observed in several spots around Fairbanks, including -3°F at Goldstream Creek and a very chilly -10°F near Smith Lake on UAF's North Campus. The Poker Flat Research Range was even colder at -14°F: not bad for this time of year.
Farther afield, sub-minus 10°F occurred in a number of other remote places, including -17°F at the Jim River HADS and -15°F at the Beaver RAWS. Unsurprisingly, the Yukon River appears to be frozen over now at Beaver:
Looking west, the Koyuk River is building ice quickly, and over in the Yukon Territory the George Black Ferry was making one of the last runs of the season at Dawson today.