Meteorological 2021 Autumn Climate Summary in La Crosse WI and Rochester MN

Autumn 2021 was warmer and drier than normal across the Upper Mississippi River Valley.  More specific details can be found below.  This includes information for La Crosse WI and Rochester MN.

Temperatures...

During the meteorological autumn of 2021 (September 1-November 30), average temperatures ranged from near-normal to 6 degrees above normal across the Upper Mississippi River Valley. The highest average temperature was 54.5°F at La Crosse Regional Airport. Meanwhile, the coolest average temperature was 46.6°F at Medford Taylor County Airport. Typically autumn temperatures average from 44°F to 50°F. Rochester, MN tied 2005 and 2007 for their 4th warmest autumn (50.7°F). 11 out of their 21 warmest autumns have occurred since 1998. La Crosse, WI had their 5th warmest autumn (54.5°F). 9 out of their 16 warmest autumns have occurred since 1998. The hottest temperature was 91°F at Boscobel, WI, and Mondovi, WI on September 19. Meanwhile, the coldest temperature was 3°F at Black River Falls, WI on November 26.

Autumn 2021 Temperature Anomalies

Precipitation...

The autumn precipitation was drier than normal across the Upper Mississippi River Valley. Precipitation total ranged from 2.80" at Friendship, WI to 10.83" near Waucoma, IA. Normally, precipitation totals range from 7.50" to 8.50" south of Interstate 94 and 8.50" to 9.50" across the remainder of the area. Friendship, WI had its driest autumn (2.80"). The previous record was 4.15" in 1944. Precipitation records date back to 1930. Mather, WI had their 5th driest autumn (3.18"). Their driest autumn occurred in 1950 (2.27"). This autumn was their driest since 1953 (3.04" - 2nd driest). La Crosse, WI had their 15th driest (3.91") autumn and their driest since 1990. The autumn began abnormally dry (D0) across parts of southeast Minnesota. Southwest Wisconsin saw abnormally dry (D0) to moderate (D1) drought conditions and northeast Iowa saw abnormally dry (D0) to severe (D2) drought conditions. During the autumn, there were some small improvements across southeast Minnesota and northeast Iowa. Meanwhile, abnormally dry (D0) and moderate (D1) drought conditions developed across central and north-central Wisconsin.

Autumn 2021 Precipitation Anomalies

Snowfall... 

Snowfall was up to 2 to 6" below the 1991-2020 normal across the Upper Mississippi River Valley. Snowfall typically ranges from 2 to 5“ south of Interstate 90 and 5 to 8” across the remainder of the area. The highest snow total was 5.2” near Medford, WI.

Autumn 2021 Snowfall Anomalies

La Crosse WI...
 

Temperatures...5th Warmest From September 1 through November 30, La Crosse Regional Airport had an average temperature of 54.5°F. This was 3.1°F warmer than the 1991-2020 normal of 51.4°F. This was the 5th warmest meteorological autumn and the warmest since 2016 (average temperature 56.6°F - warmest autumn).

The table below contains the 10 warmest meteorological autumns. 

Warmest Meteorological
 Autumns in La Crosse WI
       1873-2021

Rank  Avg. Temp  Year
----  ---------  ----
  1    56.6°F    2016
  2    55.6°F    1931
  3    55.1°F    2015
  4    55.0°F    1963
  5    54.5°F    2021
  6    54.4°F    1998
  7    54.2°F    1994
  8    53.4°F    1922
  9    53.2°F    2017
 10    53.0°F    1953

The table below contains the monthly average temperatures and their departures from normal for the autumn of 2021. 

     Autumn 2021 Temperatures
          in La Crosse WI

              Average     Departure
 Month      Temperature  from Normal
 -----      -----------  -----------
September      67.2°F       +2.4°F - Tied for 
                                     11th warmest
October        57.6°F       +5.9°F - 5th warmest
November       38.7°F       +1.1°F 

Autumn         54.5°F       +3.1°F - 5th warmest

• The average high temperature was 64.5°F which was 3.6°F warmer than the 1991-2020 normal of 60.9°F. This was the 4th warmest and the warmest since 2016.  
• The average low temperature was 44.5°F which was 2.7°F warmer than the 1991-2020 normal of 41.8°F. This was the 8th warmest and the warmest since 2016.
   
• The warmest high temperature was 90°F on September 19.
• The coldest high temperature was 34°F on November 18, November 22, and November 26.
   
• The warmest low temperature was 65°F on October 2.  
• The coldest low temperature was 14°F on November 25.
   
• Temperatures averaged above normal on 56 days, below normal on 27 days and normal on 8 days.

Precipitation...15th Driest

From September 1 through November 30, La Crosse Regional Airport received 4.06 inches of precipitation. This was 3.91 inches drier than the 1991-2020 normal of 7.97 inches. This was the 15th driest meteorological autumn and the driest since 1990 (3.99 inches - 14th driest). The table below contains the 20 driest meteorological autumns.

  Driest Meteorological
 Autumns in La Crosse WI
       1873-2021

Rank  Precipitation  Year
----  -------------  ----
  1    0.82 inches   1976
  2    2.11 inches   1952
  3    2.23 inches   1953
  4    2.69 inches   1897
  5    2.77 inches   1949
  6    2.84 inches   1899
  7    2.93 inches   1939
  8    3.06 inches   1888
  9    3.24 inches   1955
 10    3.25 inches   1950
 11    3.29 inches   1932
 12    3.54 inches   1912
 13    3.98 inches   1910
 14    3.99 inches   1990
 15    4.06 inches   2021
 16    4.08 inches   1967
 17    4.12 inches   1993
 18    4.23 inches   1893
 19    4.30 inches   1918
 20    4.40 inches   1895    

The table below contains the monthly precipitation totals and their departures from normal for the autumn of 2021.

     Autumn 2021 Precipitation
          in La Crosse WI

          Precipitation   Departure
 Month        Total      from Normal
 -----    -------------  -----------
September  1.43 inches  -2.20 inches
October    1.05 inches  -1.44 inches
November   1.58 inches  -0.27 inches 

Autumn     4.06 inches  -3.91 inches - 15th Driest

• The highest daily precipitation total was 0.76 inches on November 11.  
• Measurable rain fell on 19 days (20.9%) and trace amounts fell on another 14 days (15.4%).  

Breakdown by precipitation amounts

None              58 Days
Trace             14 Days
0.01-0.09 inches  10 Days
0.10-0.24 inches   4 Days
0.25-0.49 inches   2 Days
0.50-0.99 inches   3 Days

Snowfall...Below-Normal

From September 1 through November 30, the official snow observer near La Crosse Regional Airport received 0.8 inches of snow. This was 2.9 inches below the 1991-2020 normal of 3.7 inches. The table below contains the monthly snowfall totals and their departures from normal for the autumn of 2021.

        Autumn 2021 Snowfall
          in La Crosse WI

             Snowfall     Departure
 Month        Total      from Normal
 -----    -------------  -----------
September   0.0 inches    0.0 inches
October     0.0 inches   -0.3 inches
November    0.8 inches   -2.6 inches 

Autumn      0.8 inches   -2.9 inches 

• The highest daily snowfall was 0.7 inches on November 13.
• Measurable snow fell on 2 days (2.2%) and trace amounts fell on another 2 days (2.2%). 

Breakdown by snowfall amounts

None              87 Days
Trace              2 Days
0.1-0.9 inches     2 Days

• Greatest snow depth was a trace on November 14.

Sky...

• It was clear on 49 days.
• It was partly cloudy on 31 days.
• It was cloudy on 11 days.

Sea Level Pressure...

• Highest was 30.48 inches on November 19.
• Lowest was 29.37 inches on November 11.

Winds...

• Highest sustained wind was 41 mph from the southwest on September 20.
• Highest wind gust was 57 mph from the west southwest on September 20.

Rochester MN...
 

Autumn of 2021 was much warmer and drier than normal at Rochester, MN. It was tied for the 4th warmest with 2005 and 2007. 14 out of their 25 warmest autumns have occurred since 1998. More details can be found below. Temperatures...Tied for the 4th Warmest with 2005 and 2007 From September 1 through November 30, Rochester International Airport had an average temperature of 50.7°F. This was 3.2°F warmer than the 1991-2020 normal of 47.5°F. This was tied for the 4th warmest meteorological autumn with 2005 and 2007, and the warmest since 2016 (average temperature of 53.1°F - the warmest meteorological autumn.

The table below contains the 10 warmest meteorological autumns. 

Warmest Meteorological
 Autumns in Rochester MN
       1886-2021

Rank  Avg. Temp  Year
----  ---------  ----
  1    53.1°F    2016
  2    52.6°F    1963
  3    52.0°F    2015
  4    50.7°F    2021
       50.7°F    2007
       50.7°F    2005
  7    50.5°F    1953
  8    50.3°F    2011
  9    50.1°F    1998
 10    50.0°F    2001
       50.0°F    1994
       50.0°F    1948

The table below contains the monthly average temperatures and their departures from normal for the autumn of 2021. 

     Autumn 2021 Temperatures
          in Rochester MN

              Average     Departure
 Month      Temperature  from Normal
 -----      -----------  -----------
September      63.1°F       +2.0°F 
October        53.4°F       +5.5°F - 10th Warmest
November       35.5°F       +1.9°F 

Autumn         50.7°F       +3.2°F - Tied for 4th Warmest

• The average high temperature was 60.9°F which was 3.8°F warmer than the 1991-2020 normal of 57.1°F. This was the 5th warmest and the warmest since 2016.  
• The average low temperature was 40.5°F which was 2.5°F warmer than the 1991-2020 normal of 38.0°F. This was tied for 9th warmest with 1971 and the warmest since 2016.  
   
• The warmest high temperature was 86°F on September 19.
• The coldest high temperature was 30°F on November 18 and November 25.
   
• The warmest low temperature was 61°F on September 19.  
• The coldest low temperature was 11°F on November 25 and November 26.
   
• Temperatures averaged above normal on 56 days, below normal on 30 days and normal on 7 days.

Precipitation...Drier than normal

From September 1 through November 30, Rochester International Airport received 5.15 inches of precipitation. This was 2.68 inches drier than the 1991-2020 normal of 7.83 inches. The table below contains the monthly precipitation totals and their departures from normal for the autumn of 2021.

     Autumn 2021 Precipitation
          in Rochester, MN

          Precipitation   Departure
 Month        Total      from Normal
 -----    -------------  -----------
September  1.63 inches  -1.97 inches
October    1.63 inches  -0.80 inches
November   1.89 inches  +0.09 inches 

Autumn     5.15 inches  -2.68 inches 

• The highest daily precipitation total was 1.42 inches on November 10.  
• Measurable rain fell on 22 days (24.2%) and trace amounts fell on another 10 days (11%).  

Breakdown by precipitation amounts

None              59 Days
Trace             10 Days
0.01-0.09 inches  14 Days
0.10-0.24 inches   1 Day
0.25-0.49 inches   4 Days
0.50-0.99 inches   1 Day
1.00-1.99 inches   1 Day

Snowfall...Tied for 12th Least with 1933

From September 1 through November 30, the official snow observer near Rochester International Airport received 0.6 inches of snow. This was 4.8 inches below the 1991-2020 normal of 5.4 inches. This was tied with 1933 for the 12th least amount of snow in autumn. The table below contains the 20 autumns with the least amount of snow.

 Snowless Meteorological
 Autumns in Rochester MN
       1933-2021

Rank    Total Snow   Year
----    ----------   ----
  1       Trace      1941
  2     0.1 inches   2012
        0.1 inches   1960
  4     0.2 inches   2011
  5     0.3 inches   1973
        0.3 inches   1963
  7     0.4 inches   2001
        0.4 inches   1962
  9     0.5 inches   1999
        0.5 inches   1967
        0.5 inches   1935
 12     0.6 inches   2021
        0.6 inches   1933
 14     0.7 inches   1998
        0.7 inches   1980
        0.7 inches   1958
 17     0.9 inches   2007
 18     1.0 inches   2016
 19     1.1 inches   1965
 20     1.3 inches   2013
        1.3 inches   2010
        1.3 inches   2003
        1.3 inches   1948

The table below contains the monthly snowfall totals and their departures from normal for the autumn of 2021.

        Autumn 2021 Snowfall
          in Rochester MN

             Snowfall     Departure
 Month        Total      from Normal
 -----    -------------  -----------
September   0.0 inches    0.0 inches
October     0.0 inches   -0.9 inches
November    0.6 inches   -3.9 inches - Tied for 19th Least

Autumn      0.6 inches   -4.8 inches - Tied for 12th Least

• The highest daily snowfall total was 0.3 inches on November 12 and November 13.
• Measurable snow fell on 2 days (2.2%) and trace amounts fell on another 5 days (5.5%). 

Breakdown by snowfall amounts

None              84 Days
Trace              5 Days
0.1-0.9 inches     2 Days

• Greatest snow depth was a trace on November 12, November 14, and November 15.

Sky...

• It was clear on 51 days.
• It was partly cloudy on 30 days.
• It was cloudy on 10 days.

Sea Level Pressure...

• Highest was 30.45 inches on November 19.
• Lowest was 29.46 inches on November 12.

Winds...

• Highest sustained wind was 37 mph from the southwest on November 21.
• Highest wind gust was 49 mph from the southeast on November 16.