Update January 24: the airport temperature data from Eagle yesterday was incorrect, as the ASOS aspirator has failed (information courtesy of Rick). The high temperature at the COOP station was "only" 42 °F - still a record for the date, but not for the month. However, with warmth aloft intensifying over the next few days, many more temperature records will undoubtedly fall.
This post will need updating when the final data is in, but the current [noon AKST] temperature of 54 °F at Eagle airport appears to be the highest January temperature on record for any observing station in Eagle, the previous January record being 50 °F in 1981.
Today's temperature is also higher than any temperature recorded in November, December, or March in Eagle; the only higher temperature in the winter season was 57 °F on February 10, 2006.