Autumn 2023 Astronomical Climate Summary

Temperatures:

During Astronomical Autumn 2023 (September 23 through December 20), average temperatures ranged from 39.1°F at Medford Taylor County Airport, WI (AWOS) to 46.3°F at Decorah, IA (COOP) in the Upper Mississippi River Valley. Temperature anomalies ranged from 1°F to 6°F warmer than normal. The hottest temperature was 100°F at Boscobel Airport, WI (ASOS) on September 3. Meanwhile, the coldest temperature was -6°F at Black River Falls, WI (RAWS) on November 28.

Precipitation:

Precipitation was highly variable across the Upper Mississippi River Valley. Precipitation varied from 4.40" near Oelwein, IA (COOP) to 16.72" at Black River Falls Sewage, WI (COOP). Precipitation anomalies ranged from 4" below normal to 8" wetter than normal. The highest one-day precipitation was 6.23" at Black River Falls Sewage, WI (COOP) from October 24 through October 25.

During autumn, moderate (D1) to extreme (D3) drought improved from 99.85% to 64.9% of the La Crosse Hydrologic Service Area (HSA). Extreme (D3) drought improved from 41.9% to 20.1% of the HSA.

Snowfall:

Autumn snowfall ranged trace at Alma Dam 4, WI (COOP) to 7.8" at Chatfield 9 ESE, MN (CoCoRaHS). These values were up to 10 inches below normal. The snowiest day was 3.9" at Lanesboro 0.2 SSW, MN (CoCoRaHS) from 7 AM on October 31 to 7 AM on November 1.

The information below details astronomical autumn 2023 temperatures, precipitation, and snowfall for La Crosse WI, and Rochester MN.

La Crosse WI...
 

The astronomical Autumn of 2023 was warmer and drier than normal in La Crosse, WI. More details can be found below.

Temperatures - 7th Warmest

During astronomical autumn (September 30 through December 20), La Crosse Regional Airport had an average temperature of 45.4°F. This was 5.2°F warmer than the 1873-2023 long-term average of 40.2°F. This was the 7th warmest autumn. 5 of the 11 warmest autumns have occurred since 2015 (2015 - warmest, 2021 - 3rd warmest, 2016 - 6th warmest, 2023 - 7th warmest, and 2017 - 11th warmest). The table below lists the 10 warmest autumns in La Crosse, WI.

Ten Warmest Astronomical Autumns
     in La Crosse, WI
        1873-2023

         Average
Rank   Temperature   Year
----   -----------   ----
  1      47.1°F      2015
  2      47.0°F      1998
  3      46.2°F      2021
  4      46.1°F      2001
  5      45.7°F      1931
  6      45.5°F      2016
  7      45.4°F      2023
  8      44.7°F      1994
  9      44.6°F      1953
 10      44.4°F      1881

• The average high temperature was 53.6°F which was 4.9°F warmer than the 1873-2023 long-term average of 48.7°F. This was the 9th warmest and the warmest since 2021 (55.6°F - 3rd warmest).

• The average low temperature was 37.1°F which was 5.4°F warmer than the 1873-2023 long-term average of 31.7°F. This was the 6th warmest and the warmest since 2015 (38.3°F - warmest).  

• The hottest high temperature was 91°F on October 1.

• The coldest high temperature was 24°F on November 27 and November 28.

• The warmest low temperature was 68°F on September 30 and October 1.

• The coldest low temperature was 7°F on November 28.

Precipitation - Drier than Average

• During astronomical autumn, La Crosse Regional Airport received 5.37 inches of precipitation. Which was 0.42 inches drier than the 1873-2023 long-term average of 5.79 inches.  
• The wettest day occurred on October 13 when 1.25 inches fell.
• No precipitation fell on 54 days (60.7%).
• A trace of precipitation fell on 14 days (15.7%).
• Measurable (0.01 inches or greater) fell on 21 days (23.6%).

Snowfall - Below Average

• During astronomical autumn, the official NWS snow observer near La Crosse Regional Airport received 3.9 inches of snow. This was 6.3 inches below the 1897-2023 long-term average of 10.2 inches. 
• The snowiest day occurred on November 26 when 1.5 inches fell.
• No snow fell on 77 days (85.6%).
• A trace of snow fell on 8 days (9%).
• Measurable (0.1" or greater) fell on 4 days (4.5%). 

Snow Depth - Below Average

• During astronomical autumn, the official NWS snow observer near La Crosse Regional Airport had an average snow depth of 0.1 inches. This was 0.5 inches below the 1893-2020 long-term average of 0.6 inches. 
• The greatest snow depth was 2 inches on November 27.

Rochester MN...

The astronomical Autumn of 2023 was warmer and wetter than normal at Rochester, MN. More details can be found below.

Temperatures - 6th Warmest

During astronomical autumn, Rochester International Airport had an average temperature of 42.4°F. This was 4.8°F warmer than the 1886-2023 long-term average of 37.6°F. This was the 6th warmest. 10 out of the 16 warmest autumns have occurred since 1998. The table below lists the 10 warmest autumns in Rochester, MN.

Ten Warmest Astronomical Autumns
     in Rochester MN
        1886-2023

         Average
Rank   Temperature   Year
----   -----------   ----
  1      43.9°F      2015
         43.9°F      2001
  3      43.6°F      1931
  4      42.7°F      1998
  5      42.6°F      2021
  6      42.4°F      2023
  7      42.0°F      2012
         42.0°F      1953
  9      41.9°F      2011
 10      41.8°F      1913

• The average high temperature was 51.6°F which was 4.6°F warmer than the 1886-2023 long-term average of 47°F. This was the 11th warmest and the warmest since 2021 (52°F - 8th warmest).  

• The average low temperature was 33.3°F which was 5.1°F warmer than the 1886-2023 long-term average of 28.2°F. This was tied for the 5th warmest with 2021.

• The warmest high temperature was 90°F on September 30 and October 1.

• The coldest high temperature was 19°F on November 27.

• The warmest low temperature was 67°F on September 30.

• The coldest low temperature was 0°F on November 28.

Precipitation - Wetter than Normal

• During astronomical autumn, Rochester International Airport received 7.06 inches of precipitation. Which was 1.71 inches wetter than the 1886-2023 long-term average of 5.35 inches. 
• The wettest day occurred on October 24 when 2.26 inches fell.
• No precipitation fell on 47 days (52.8%).
• A trace of precipitation fell on 15 days (16.9%).
• Measurable (0.01 inches or greater) fell on 27 days

Snowfall - 8th Least

• During astronomical autumn, the official NWS snow observer near Rochester International Airport received 2.8 inches of snow.  This was 9.5 inches less than the 1933-2023 long-term average of 12.3 inches. This was the 8th least and the least since 2001 (1 inch - 5th least). The table below lists the 10 least amount of snow during autumn in Rochester, MN.

  Ten Least Amount of Snow 
   in Astronomical Autumn
     in Rochester MN
        1933-2023
         
Rank    Snowfall      Year
----    --------      ----
  1    0.5 inches     1960
  2    0.8 inches     1935
       0.8 inches     1933
  4    0.9 inches     1967
  5    1.0 inch       2001
  6    1.1 inches     1962
  7    1.5 inches     1965
  8    2.8 inches     2023
  9    3.0 inches     1944
 10    3.1 inches     2015

• The snowiest day occurred on October 31 when 1.1 inches fell.
• No snow fell on 76 days (85.4%).
• A trace of snow fell on 5 days (5.6%).
• Measurable (0.1 inches or greater) fell on 8 days (9%).

Snow Depth - Tied for Least with 11 Other Years

• During astronomical autumn, the official NWS snow observer near Rochester International Airport had an average snow depth of 0 inches. This was 0.8 inches less than the 1944-2023 long-term average of 0.8 inches. 
• The greatest snow depth was 1 inch on October 31.