18 Straight Warm Months

Graph of February 2017 temperatures and departures in the Twin Cities
February 2017 temperatures and departures in the Twin Cities

 

Minnesota is in the grips of a historic warm streak, now standing at 18 months in many locations, including the Twin Cities.

February 2017 started off relatively tame, with the usual flip-flopping between warm and cold conditions for the first nine days. The 10th, however, kicked off a 2-week spell of significantly warm weather, including a six-day run between the 17th and 22nd that broke numerous records. In the Twin Cities, daily temperatures were above averages on 23 of 28 days, and the average monthly temperature has now been above the 1981-2010 normal for 18 months in a row.

As a month, February 2017 was among the warmest on record across the state. It ranked in the top-10 at Duluth, the Twin Cities, Rochester, and St. Cloud--where it was 3rd warmest since 1895. 

The Twin Cities have not recorded average monthly temperatures that were below 1981-2010 normals since August 2015. This is the longest above-average monthly temperature streak of any kind on record in the Twin Cities, though it is worth noting that the "normals" refresh every 10 years, and procedures for calculating them have changed over time. As of this writing, only five months out of the last 33 (back to June 2014) have been below normal in the Twin Cities. The second longest streak on record was 16 months, from June 2011 through September 12.

This climatological decade (beginning January 2011), over 70% of months have been above the 1981-2010 normals. In the previous climatological decade, 68% of months were above the 1971-2000 normals, and the Twin Cities has not had a string of 10 or more cool months since 1964-65. Indeed, the whole of Minnesota has been warming rapidly since about 1970, making above-normal temperatures more likely than below-normal ones, even as the baseline values are updated to reflect the warmer conditions.  

Twin Cities Average Monthly Temperatures

                Avg    Dept. from
Month     Year  Temp   1981-2010 Normal
---------------------------------------------
September 2015  67.9   + 5.9
October   2015  52.1   + 3.2
November  2015  41.3   + 7.6
December  2015  30.2   +10.5
January   2016  17.6   + 2.0
February  2016  24.9   + 4.0
March     2016  41.3   + 8.5
April     2016  48.1   + 0.6
May       2016  61.3   + 2.2
June      2016  71.3   + 2.4
July      2016  75.2   + 1.4
August    2016  73.4   + 2.2
September 2016  66.1   + 4.1
October   2016  52.9   + 4.0
November  2016  44.1   +10.4
December  2016  20.9   + 1.2
January   2017  20.9   + 5.3
February  2017  31.2   +10.3

Last modified: March 1, 2017
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