Astronomical Spring 2018 Climate Summary

While astronomical Spring 2018 (March 20-June 20) temperatures averaged close to normal, they were far from that.  From March 31 through April 20, temperatures averaged double digits below normal.  This was the coldest ever recorded for this time period.  Meanwhile, in contrast, the area experienced the warmest May 1 through June 20 ever recorded.  This warmth accelerated plant growth, so by the end spring plants were close to normal or slightly ahead of schedule. The maps below are courtesy of the Midwestern Regional Climate Center.

March 31-April 20 Temperature Departures	May 1- June 20 Temperatures Departures	Spring 2018 Temperature Departures

As far as precipitation goes, it was another wet astronomical spring across the Upper Mississippi River Valley.  The wettest locations were along and just south of the Interstate 90 corridor.  La Crosse WI has had 8 of their 20 wettest springs occur this century.  Meanwhile, Rochester MN has had 9 of their 20 wettest springs occur this century.  During April, much of this precipitation fell as snow.  It was the snowiest spring in La Crosse WI and tied for the 4th snowiest at Rochester MN.  The maps below are courtesy of the Midwestern Regional Climate Center.

Spring 2018 Precipitation Departures	Spring 2018 Snowfall Departures

More details for La Crosse, WI and Rochester MN can be found below.
 

...Astronomical Spring was Warmer and Wetter-than-Average at La Crosse WI...
 

During the astronomical spring of 2018, temperatures averaged warmer (average temperature was 55.5°F or +1°F departure from average) and wetter (total precipitation 13.78 inches which was +3.67 inches greater than average - tied for 19th wettest) than average at La Crosse Regional Airport.  It was the snowiest astronomical spring (19.0 inches which was 14.1 inches greater than average) and was tied for 7th greatest average snow depth.  More details on these statistics can be found below.

Temperatures - 52nd Warmest

From March 20 through June 20, La Crosse Regional Airport had an average temperature of 55.5°F.  This was 1°F warmer than the long-term (1873-2018) average of 54.5°F.  

• The average high temperature was 65.9°F.  This was 1.3°F warmer than the long-term average of 64.6°F.  
• The average low temperature was 45.1°F.  This was 0.7°F warmer than the long-term average of 44.4°F.  
   
• The warmest high temperature was 98°F on May 27 and June 17.
• The coldest high temperature was 27°F on April 15.
   
• The warmest low temperature was 77°F on June 17.
• The coldest low temperature was 15°F on April 1 and April 5.
   
• There were 7 days in which the high temperature reached or exceeded 90°F.
• There were 30 days in which the low temperature was 32°F or colder.  

Precipitation - Tied for 19th Wettest

From March 20 through June 20, La Crosse Regional Airport received 13.78" of precipitation.  This was 3.67" wetter than the long-term (1873-2018) average of 10.11". This tied 1967 for the 19th wettest astronomical spring in La Crosse WI. The table below contains the 20 wettest astronomical springs in La Crosse WI.  

    Top 20 Wettest Astronomical Springs
              in La Crosse WI
                 1873-2018

              Precipitation
    Rank          Total         Year
    ----      -------------     ----
      1       23.08 inches      1993
      2       18.87 inches      1899
      3       18.47 inches      2004
      4       18.19 inches      2008
      5       18.10 inches      2011
      6       17.51 inches      1973
      7       16.58 inches      2013
      8       16.20 inches      1991
      9       16.19 inches      1892
     10       16.13 inches      1960
     11       15.39 inches      1880
     12       15.27 inches      2017
     13       14.72 inches      2014
     14       14.68 inches      1945
     15       14.53 inches      1876
     16       14.39 inches      1888
     17       14.03 inches      1908
     18       13.83 inches      2001
     19       13.78 inches      2018
              13.78 inches      1967

Measurable rain (0.01 inches or greater) fell on 36 days (38.7%) and trace amounts on 13 days (14%).  

Number of days with...

       0.01 inches or more       36 Days
       0.10 inches or more       26 Days
       0.50 inches or more       11 Days
       1.00 inches or more        5 Days

The wettest spring day was 1.22" on May 3. 

Snowfall - Greatest

From March 20 through June 20, the snow observer near La Crosse Regional Airport received 19.0".  This was 14.1" greater than the long-term (1897-2018) average of 4.9 inches. The was the snowiest astronomical spring.  The previous record was 17.0" in 1973. The table below contains the ten snowiest astronomical springs in La Crosse WI.  

    Top 10 Snowiest Astronomical Springs
              in La Crosse WI
                 1897-2018

                 Snowfall
    Rank           Total        Year
    ----       -----------      ----
      1        19.0 inches      2018
      2        17.0 inches      1899
      3        15.6 inches      1952
      4        14.5 inches      1911
      5        13.9 inches      1993
      6        13.4 inches      1931
               13.4 inches      1909
      8        13.3 inches      1900
      9        13.0 inches      1934
     10        12.4 inches      1975
               12.4 inches      1910

Number of days with...

     No Snowfall - 78 Days - 83.9%
     Trace       -  9 Days -  9.7%
     < 1"        -  2 Days -  2.2%
     1 to 2.9"   -  1 Day  -  1.1%
     3 to 5.9"   -  1 Day  -  1.1%
     6 to 8.9"   -  2 Days -  2.2%

The snowiest day was 6.7 inches on April 3. 

Snow Depth - Tied for 7th Greatest

The average snow depth was 0.5".  This was 0.4" greater than the long-term (1893-2018) average. This was tied with 1933, 1951, 1955, and 1973 for the 7th greatest and it was the greatest average snow depth since 2013 (0.6 inches).  The table below contains the 10 greatest average snow depth during astronomical springs in La Crosse WI.  

    Top 10 Greatest Average Snow Depth 
        during Astronomical Springs
              in La Crosse WI
                 1893-2018

                 Average 
    Rank       Snow Depth       Year
    ----       ----------       ----
      1         1.0 inch        1959
                1.0 inches      1956
      3         0.6 inches      2013
                0.6 inches      1965
                0.6 inches      1962
                0.6 inches      1899
      7         0.5 inches      2018
                0.5 inches      1973
                0.5 inches      1955
                0.5 inches      1951
                0.5 inches      1933

Number of days with...

     No Snowfall - 77 Days - 82.8%
     Trace       -  3 Days -  3.2%
     1 to 2.9"   -  5 Day  -  5.4%
     3 to 5.9"   -  5 Day  -  5.4%
     6 to 8.9"   -  3 Days -  3.2%

The greatest snow depth was 7 inches on April 4 and April 19.

...Astronomical Spring was slightly cooler and Wetter-than-Average in Rochester MN...

During the astronomical spring of 2018, temperatures averaged slightly cooler (average temperature 51.8F or -0.3F departure), wetter (total precipitation 13.19 inches which was +3.01 inches greater than average - tied for 20th wettest), and snowier (17.0 inches which was 5.7 inches snowier than average - tied for 4th snowiest) astronomical spring at Rochester International Airport. More details on these statistics can be found below.

Temperatures - 56th Warmest
 

From March 20 through June 20, Rochester International Airport had an average temperature of 51.8°F.  This was -0.3°F cooler than the long-term (1887-2018) average of 52.1°F.  

• The average high temperature was 61.5°F.  This was 1.2°F degrees cooler than the long-term average of 62.8 degrees.
• The average low temperature was 42.1°F.  This was 0.6°F warmer than the long-term average of 41.5 degrees.  
   
• The warmest high temperature was 95°F on May 28. 
• The coldest high temperature was 23°F on April 4.
   
• The warmest low temperature was 72°F on June 16 and June 17.
• The coldest low temperature was  6°F on April 4.
   
• There were 8 days in which the high temperature reached or exceeded 90°F.  This was the 2nd greatest total for a spring.  The only year with more 90 degree days was 1934 with 15 days.
• There were 34 days in which the low temperature was 32°F or colder.  

Precipitation - 20th wettest
 

From March 20 through June 20, Rochester International Airport received 13.19 inches of precipitation.  This was 3.01 inches wetter than the long-term (1887-2018) average of 10.18 inches.  The table below contains the 20 wettest astronomical springs in Rochester MN.  

    Top 20 Wettest Astronomical Springs
              in Rochester MN
                 1886-2018

              Precipitation
    Rank          Total         Year
    ----      -------------     ----
      1       20.35 inches      2013
      2       19.81 inches      2001
      3       18.67 inches      2000
      4       18.04 inches      1993
      5       17.12 inches      2004
      6       16.10 inches      1930
      7       16.00 inches      1990
      8       15.59 inches      2008
      9       14.98 inches      1974
     10       14.77 inches      1914
     11       14.72 inches      1938
     12       14.62 inches      2011
     13       14.39 inches      1945
     14       14.29 inches      1954
     15       14.15 inches      2015
     16       14.03 inches      1999
     17       13.63 inches      2014
     18       13.42 inches      1991
     19       13.36 inches      1967
     20       13.19 inches      2018

Measurable rain (0.01 inches or greater) fell on 37 days (39.8%) and trace amounts on 12 days (12.9%).  

Number of days with...

       0.01 inches or more       37 Days
       0.10 inches or more       24 Days
       0.50 inches or more       10 Days
       1.00 inches or more        4 Days

The wettest spring day was 1.61 inches on May 11.

Snowfall - Tied for 4th Greatest

From March 20th through June 20th, the snow observer near Rochester International Airport received 17.0".  This was 11.3" greater than the long-term (1917-2018) average of 4.9".  The was tied with 1944 for the 4th greatest snowfall during an astronomical spring.   The table below contains the 10 snowiest astronomical springs in Rochester MN.  

    Top 10 Snowiest Astronomical Springs
              in Rochester MN
                 1916-2018

                 Snowfall
    Rank           Total        Year
    ----       -----------      ----
      1        22.6 inches      1952
      2        21.9 inches      1983
      3        18.7 inches      2013
      4        17.0 inches      2018
               17.0 inches      1944
      6        16.2 inches      1934
      7        15.6 inches      1988
      8        15.4 inches      1962
      9        14.8 inches      1993
     10        14.2 inches      1985
               14.2 inches      1979

Number of days with...

     No Snowfall - 80 Days - 86.0%
     Trace       -  6 Days -  6.5%
     < 1"        -  3 Days -  3.2%
     1 to 2.9"   -  2 Day  -  2.2%
     3 to 5.9"   -  1 Day  -  1.1%
     6 to 8.9"   -  1 Days -  1.1%

The snowiest day was 7.4 inches on April 3. 

Snow Depth - 

The average snow depth was 0.5".  This was 0.2" greater than the long-term (1945-2018) average of 0.3". 

Number of days with...

     No Snowfall - 78 Days - 83.9%
     Trace       -  2 Days -  2.2%
     1 to 2.9"   -  5 Day  -  5.4%
     3 to 5.9"   -  6 Day  -  6.5%
     6 to 8.9"   -  2 Days -  2.2%

The greatest snow depth was 7 inches on April 4.