The January Thaw of 2017 was one of the most prolonged January thaws on record, going back to 1873.
"January Thaws" are part of Minnesota's climate. Nearly every year, the mercury climbs above freezing sometime in January, bringing a brief respite to a Minnesota Winter. A January Thaw is defined as two or more consecutive days where the maximum temperature is above 32 degrees. For the Twin Cities this happens about 93% of the time. A White Christmas in the Twin Cities (one inch or more of snow cover on Christmas Day) happens about 72% of the time, thus it more likely to have a "January Thaw" than a White Christmas.
The January Thaw of 2017 was very impressive and set some new records for consecutive nights that stayed above freezing (32 degrees F). In the Twin Cities there were four nights in a row that the mercury remained above freezing, from January 20 to 23. St. Cloud also had three nights that stayed above 32 degrees, also setting a record there.
The thaw was not confined to central and southern Minnesota. International Falls had six days in a row with a maximum temperature above 32 degrees, with two minimum temperatures of 33 degrees, yet International Falls only lost four inches of snow cover during this period.
The last time there was not a January Thaw in the Twin Cities was in 2011. In 2009 there was one maximum temperature of 46 degrees, but that occurred on the 31st and fell short of the two-consecutive day criteria.