In Duluth, climate data shows we get above freezing for at least a couple days in January about 60 percent of all years, according to a report that University of Minnesota climate expert Mark Seeley prepared last year for the Minnesota Department of Transportation.
According to a News Tribune analysis, Duluth has had a snow-melting thaw in January in all but one winter -- 2004 -- the past 12 years, though it hasn't always happened during the third week of the month.
Looking at just the third week in January, Duluth has had a significant thaw in six of the past 12 winters, including the last four years in a row.
Some winters are so brutally cold that no January thaw ever comes, including 1977-1979 and both 1995 and 1996.
Others are so warm that we may not even notice a thaw. January 2002 was above normal all month. Yet from Jan 25-27 temperatures went even higher, topping out at 42 degrees -- about 20 degrees above normal and perfect timing to be called a January thaw.
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Not all scientists agree it's a real phenomenon. One study found that the thaw may seem regular and come during more than half of all years but also may be just a statistical anomaly.
In Duluth, average daily temperatures drop until Jan. 18, about one month after the shortest day of the year. After that, average temperatures begin their march to the highest of the year, in late July, about one month after the longest days of the year.
In some areas the January thaw really isn't a thaw, but a regularly occurring warm-up with temperatures 10-20 degrees above normal -- but still below freezing.
