National Weather Service United States Department of Commerce
Halloween is celebrated in the United States on October 31st.  Below are some weather statistics for La Crosse, WI and Rochester, MN for this day.

"October 31st marks the date of an astronomical “cross-quarter” day, which under traditional agricultural calendar systems marks the mid-point of an astronomical season.  These days figured prominently in many cultures, especially those in northern Europe, where the seasonal markers and cross-quarters were widely celebrated with feasts and general merrymaking.  Today everyone recognizes the 31st as Halloween, but few understand its significance in ancient cultures.  To the Celts it represented the beginning of the long nights of winter, and with those came dark connotations of death and suffering.  Their observance of Samhain was eventually Christianized into All Saints Day, preceded by All Hallows Eve, a time to remember the souls of those who died during the previous year.   If you see ghosts and goblins prowling your neighborhood that evening, you better give them treats!"  (Source:  US Naval Observatory)


La Crosse, WI:

The following statistics comprise 147 years of data.  From 1872 through 1950, the data came from various locations in downtown La Crosse. Since 1950, the data has been gathered at La Crosse Regional Airport.  Due to the NWS office being closed down in the Autumn of 1985, no observations were taken during that year.

Halloween in La Crosse, WI
(Period of Record 1872-2019)
1981-2010 Normals
Records
Maximum Temperature 53°F Warmest High Temperature 79°F 1950
1933
Coldest High Temperature 31°F 1873
Minimum Temperature 36°F Warmest Low Temperature 58°F 1950
Coldest Low Temperature 18°F 1917
1873
Average Temperature 44°F Warmest Average Temperature 68.5°F 1950
Coldest Average Temperature 24.5°F 1873
Precipitation 0.06" Wettest 2.04" 1984
Snow 0" Snowiest 2.4" 1926
Snow depth at 7 AM 0" Greatest Snow Depth at 7 AM 2" 1917


The odds of having any precipitation at all on Halloween is 44.2% (65 out of 147).  There has been measurable (0.01" or greater) precipitation on 43 Halloweens (29.3%) and trace amounts (less than 0.01") on 22 Halloweens (15.0%). 

Since 1897, it has snowed on 13 of 120 Halloweens (10.8%).  The only Halloweens with measurable snowfall were in 1926 (2.4") and 1995 (0.5").  The La Crosse area has not seen measurable snow on Halloween since 1995 (0.5").

Last Halloween (2019), the high temperature was 37°F (tied for the 8th coldest) and the low temperature was 27°F.  The average temperature was 32°F.  No precipitation fell and the average wind speed was 9.7 mph.

Rochester, MN:

The following statistics comprise 107 years of data. From 1886 through 1931, the data came from several cooperative observers in the Rochester area. Since 1932, the data has been gathered at Rochester International Airport. No data was taken on Halloween from 1889 to 1891, in 1908, from 1921 to 1927, and in 1933.

Halloween in Rochester, MN
(Period of Record 1894-2019)
1981-2010 Normals
Records
Maximum Temperature 51°F Warmest High Temperature 78°F 1950
Coldest High Temperature 30°F 1996
1917
Minimum Temperature 34°F Warmest Low Temperature 54°F 1974
Coldest Low Temperature 15°F 1993
Average Temperature 42°F Warmest Average Temperature 65.0°F 1950
Coldest Average Temperature 23.0°F 1996
Precipitation 0.06" Wettest 1.31" 1935
Snow 0.1" Snowiest 3.5" 1929
Snow Depth at 7 AM 0" Greatest Snow Depth at 7 AM 4" 1929


The odds of having any precipitation at all on Halloween is 41.1% (44 out of 107).  There has been measurable (0.01" or greater) precipitation on 33 Halloweens (30.8%) and trace amounts (less than 0.01") on 11 Halloweens (10.3%).  

Since 1928, it has snowed on 16 out of 95 Halloweens (16.8%).  Measurable snow has fallen on 8 Halloweens (1929 - 3.5", 1932 -1.5", 1954 - 0.6", 1966 - 0.1", 1970 - 0.1", 1989 - 0.4", 1991 - 0.4", and 1995 - 1.7").  The last measurable snowfall on Halloween occurred in 1995 (1.7 inches).

Last Halloween (2019), the high temperature was 33°F (tied with 2002 for the 4th coldest) and the low temperature was 19°F (tied with 1930, 1951, and 1954 for 6th coldest).  The average temperature was 26°F (5th coldest).  No precipitation fell and the average wind speed was 9.5 mph.


Animated Pumpkin

The following weather events have occurred on Halloween in southeast Minnesota, northeast Iowa, and western Wisconsin:

  • In 1926, La Crosse WI received 2.4 inches of snow.  This was their snowiest Halloween.
  • In 1929, Rochester MN received 3.5 inches of snow. This was their snowiest Halloween.
  • In 1935, Rochester MN received 1.31 inches of rain. This was their wettest Halloween.
  • In 1984, La Crosse WI received 2.04 inches of rain. This was their wettest Halloween.
  • In 1991, a low-pressure system developed on Halloween morning over southeast Texas and moved rapidly north-northeast, reaching its maximum intensity (984 mb) just east of La Crosse, WI on the afternoon of November 1st. This storm became known as the "Halloween Blizzard" in most of Minnesota and the "Halloween Ice Storm" in Iowa and portions of southeast Minnesota.

    Snow moved into southern Iowa during the afternoon of October 30th and then spread into northern Iowa and Minnesota early on October 31st. Warm air aloft wrapping around this low-pressure area caused the snow to change into a mixture of snow, sleet, and freezing rain by mid-morning on Halloween across southeast Minnesota and much of eastern Iowa, and this mixture continued until the late afternoon of November 1st. One to two inches of ice accumulated from southwest Iowa into north central Iowa, and from 2-3" of ice accumulated across south central and southeast Minnesota.
     
    Snowfall Totals From October 31st through November 3rd, 1991

    In Iowa, Interstate 35 was closed down by fallen power lines. 80,000 homes were without power and there was $63 million in utility damage. Ten to fifteen percent of the corn crop was still in the fields and the combination of ice, snow, and wind from this storm flattened some fields. Crop damage was estimated up to $5 million. This storm is considered the most costly ice storm in Iowa history. It took over a week to restore power in some rural areas. Governor Terry Branstad declared 52 of 99 counties as disaster areas.

    In south central and southeast Minnesota, 11 counties were declared federal disaster areas due to this ice storm. The total damage was $11.7 million. According to the National Weather Service publication Storm Data, "at least 20,000 people experienced power outages from October 31st to November 2nd as many power lines and poles snapped under the weight of the ice. Many rural areas were without power for about a week. Governor Arne H. Carlson declared a state of emergency in Freeborn and Mower counties. The National Guard was called upon to help provide generators to rural farmsteads. The National Guard armory and a local mall in Albert Lea were both used as the shelter for many stranded motorists November 1st and 2nd. At the height of the storm, an 180 mile long stretch of interstate 90 from South Dakota border to Rochester was closed."
     

    During the evening of November 1st, arctic air moved into the region, changing the precipitation to all snow. The snow continued until midday on November 2nd. 6 to 10" fell across Winona and Houston counties in southeast Minnesota, and La Crosse county in southwest Wisconsin. Meanwhile, 3 to 6" of snow fell across the remainder of southeast Minnesota, portions of western Wisconsin, and a small portion of northeast Iowa. These amounts are small in comparison to the snowfall from Red Wing, MN northward to the Duluth, MN area. This winter storm dropped 28.4" of snow on the Twin Cities (single storm record for the metropolitan record) while Duluth received 36.9" of snow (the largest single storm total in MN history).

    Wind speeds of 30 to 50 mph and gusts to 60 mph on November 1st and 2nd created blizzard conditions across eastern South Dakota, Minnesota, western Iowa, and extreme western Wisconsin. This storm closed schools, businesses, bridges, and public transportation systems for several days. Clean up was hindered by numerous accidents and abandoned vehicles.

    At least 20 people died in Minnesota due to traffic accidents or heart attacks from digging out after the storm. In addition, two Wisconsin hunters died when their boat was capsized in Lake Onalaska during the storm.

  • In 1995, La Crosse WI received 0.5 inches of snow.  This was only the second time since 1897 that measurable snow has fallen on Halloween in La Crosse.
  • In 2017, high temperatures ranged from the lower 30s to mid-40s and low temperatures ranged from the lower 20s to lower 30s.  Rochester had a high temperature of 34°F (tied with 1913 and 1951 for the 6th coldest), a low temperature of 22°F, and an average temperature of 28°F (tied for 10th coldest with 1991).  La Crosse had a high temperature of 35°F (4th coldest), a low temperature of 25°F, and a mean temperature of 30°F (tied for 8th coldest with 1913).
  • In 2019, high temperatures ranged from the upper 20s mid-30s and low temperatures ranged from the teens to upper 20s.  Rochester had a high temperature was 33°F (tied with 2002 for the 4th coldest), the low temperature was 19°F (tied with 1930, 1951, and 1954 for 6th coldest), and the average temperature was 26°F (5th coldest).  La Crosse had high temperature was 37°F (tied for the 8th coldest), the low temperature was 27°F, and the average temperature was 32°F.