August 2021 Climate Summary

Below are the August climate summaries for La Crosse, WI, and Rochester, MN.

La Crosse, WI

August 2021 Highlights...

Temperatures...

During August 2021, the average temperature was 74.3°F. This was 1.5°F warmer than the 1991-2020 normal of 72.8°F. This was tied with 1881 for the 11th warmest August and the warmest August since 2010 (75.8 degrees - 7th warmest).
The average high temperature was 84.6°F. This was 1.4°F warmer than the 1991-2020 normal of 83.2°F. This tied 1909 for the 18th warmest and the warmest since 2020 (85.9 degrees - 11th warmest).
The average low temperature was 63.9°F. This was 1.6°F warmer than the 1991-2020 normal of 62.3°F. This was the 18th warmest and the warmest since 2018 (64.5 degrees - tied with 1886 for 14th warmest).
The hottest temperature was 92°F on August 20.
The coldest temperature was 53°F on August 22.
There were 7 days with temperatures 90°F or warmer. The 1991-2020 normal is 4 days.

Rainfall...

During August 2021, a total of 11.78" of rain fell. This was 7.88" wetter than the 1991-2020 normal of 3.90". This was the 2nd wettest August. Only 2007 was wetter with 13.75".
Much of this rain fell (83.9%) on just 3 days (August 7 - 5.59", August 8 - 1.77", and August 27 - 2.52").
The wettest day was August 7 when 5.59" of rain fell. This not only set a record for the day, but it was also the wettest August and calendar days.
Measurable rain fell on 12 days and trace amounts fell on 2 days.

Records...

Wettest August 7 - 5.59" Previous Record 2.40" in 1889
Wettest August Day - 5.59" on August 7 Previous Record 4.05" on August 18, 2007
Wettest Calendar Day - 5.59" on August 7 Previous Record 5.55" on September 6, 1884

Looking Ahead to September…

The normal high temperature in La Crosse starts off at 81°F on the 1st and falls to 69°F by the end of the month. The normal low temperature starts off at 59°F on the 1st and falls to 48°F by the end of the month. The warmest September temperature on record is 101°F on September 6, 1922, and the coldest is 24°F from September 30, 1899.
The normal mean temperature for the month is 64.8°F. La Crosse’s hottest September occurred in 2015 with an average temperature of 69.3°F, and their coldest September occurred in 1918 with an average temperature of 54.8°F.
The normal September rainfall is 3.63". The wettest September was in 1881 with 10.87" of rain, while the driest September occurred in 1940, with only 0.29" of precipitation. The wettest September day occurred on September 6, 1884, when 5.55" of rain fell. Normally, there are 4 days with thunderstorms.
While typically no snow falls during September, measurable snow did fall in 1942 (0.2" on September 26).
Valley fog is quite prevalent in the area. On average, this fog reduces the visibility to a quarter-mile or less at the airport on 3 days.

August 2021 Highlights...

Temperatures...

During August 2021, the average temperature was 69.1°F. This was 0.9°F warmer than the 1991-2020 normal of 68.2°F.
The average high temperature was 79.2°F. This was 1.2°F warmer than the 1991-2020 normal of 78°F.
The average low temperature was 59°F. This was 0.7°F warmer than the 1991-2020 normal of 58.3°F.
The hottest temperature was 86°F on August 10.
The coldest temperature was 50°F on August 22.
There were no days with temperatures 90°F or warmer. The 1991-2020 normal is 1 day.

Rainfall...

During August 2021, a total of 6.74" of rain fell. This was 2.62" wetter than the 1991-2020 normal of 4.12". This was the 7th wettest August. This was the wettest August since 2007 (14.07").
The wettest day was August 27 when 3.51" of rain fell.
Measurable rain fell on 13 days and trace amounts fell on 2 days.

Records...

Looking Ahead to September…

The normal high temperature in Rochester starts off at 76°F on the 1st and falls to 66°F by the end of the month. The normal low temperature starts off at 56°F on the 1st and falls to 45°F by the end of the month. The warmest September temperature on record is 100°F on September 6, 1913, and the coldest is 22°F from September 28, 1942.
The normal mean temperature for the month is 61.1°F. Rochester’s hottest September occurred in 1908 with an average temperature of 69.5°F, and their coldest September occurred in 1993 with an average temperature of 53.6°F.
The normal September rainfall is 3.60". The wettest September was in 1986 with 10.50" of rain, while the driest September occurred in 1953, with only 0.33" of precipitation. The wettest September day occurred on September 12, 1978, when 5.98" of rain fell. Normally, there are 5 days with thunderstorms.
While typically no snow falls during September, measurable snow did fall in 1942 (0.3" on September 26) and 1961 (0.8" on September 30).