To have the weather service say their thermometers are accurate is only partly true: the siting of the Bettles ASOS at the highest (read that warmest) place in the village is a travesty - while the Bettles official low was -58.6, numerous calibrated thermometers at lower elevations in the community showed  -60 - I have a minimum recording spirit thermometer that often shows ten degrees colder than ASOS, and my house is only about 10 feet lower than the ASOS and 8 feet than weather station.  Temps at the houses along the river at the lowest point are usually 10 degrees cooler than "official" as checked by calibrated thermometers in similar conditions.  By the way - the equipment NWS has in remote locations they consider "accurate" are electronic and are suspect colder than -20.  The Salcha measurement was likely done in a low spot along the river with a spirit recording thermometer and should be correct.  While cold enough to make us put on more layers, this is not unusual.