It hasn't hit 90 degrees at the last 7 Minnesota State Fairs

It seems hard to believe for me, but the Minnesota State Fair starts Thursday.

Historical weather at the Fair typically brings a mix of mild days in the 70s, and some occasional hot steamy days in the 90s. But looking through Sate Fair weather records today, one stat jumps out.

The temperature hasn’t hit 90 degrees at the Fair since 2013. The current streak of seven straight State Fairs without a 90-degree temperature is the longest stretch since the Fair went to 12 days in 1975. (There was no State Fair in 2020 due to COVID-19.)

Here are some more weather data points on the Fair.

• The last 90-degree temperatures at the Fair occurred in 2013.

• There were six straight days of 90 degrees temperatures in 2013.

• Four days in 2013 produced high temperatures of 95 degrees or higher.

• 2013 was the third hottest Fair on record. (Average high was 88.2 degrees.)

• 1931 was the hottest Fair on record. (Average high in 1931 was 92.6 degrees!)

• It rains on average about every 3 to 4 days at the Fair historically.

• The wettest Fair was in 1977. 4.06” of rain fell on Aug. 30 causing flooding.

• In 2019 every day was in the 70s at the Fair. A new all-time attendance record of 2.1 million was set that year.

Here’s more perspective on State Fair climatology from the Minnesota Climate Working Group.

Temperatures

Although a wide variety of weather has greeted Fair-goers over the years, it's the late-summer heat waves that are perhaps most memorable. By far the highest temperature in the Fair's history was 104 degrees F, on September 10, 1931. In fact, the second-highest temperature ever recorded during the Fair was 99 F, notched the same year but two days earlier. Not surprisingly, the 1931 Fair is the current record-holder for high temperatures, averaging 92.6 F, which is 2.7 F higher than the runner-up (1922). It is worth noting that the 1931 Fair ran eight days, from September 5-12, whereas the Fair currently runs 12 days, making it less likely to sustain such high temperatures over that longer period. On the other hand, 1931's record is even more impressive considering that the entire Fair took place during September, when extremes of heat become increasing rare.

Recent steamy State Fair conditions were experienced during 2013, which was the third warmest on record and also had a record six days with 90-degree high temperatures. 2012 was quite warm as well, with an average daily maximum temperature of 87.1 degrees. The last six State Fairs, however (2014 through 2019), generally have lacked hot weather, with no 90-degree high temperatures recorded in any of those years. There wasn't even an 80 degree maximum temperature in 2019.

The coolest Minnesota State Fair was during the six-day run of the Fair from September 5-10 1898 with an average maximum temperature of 64.2 degrees. The coldest maximum temperature for the Fair is 52 degrees on September 7, 1911, and the coldest minimum temperature is 33 degrees on September 13, 1890. The coolest Fair morning in recent years was a chilly 36 degrees on September 1, 1974.

Precipitation

On average it rains about three to four days during the Fair's 12-day run. The wettest Fair was in 1977 with 9.48 inches, and the driest Fair was 2003 with only .02 inch of rain.

The largest rain event in the State Fair's history was August 30, 1977. At 8:20pm heavy rains hit the State Fairgrounds. The U of M St. Paul Campus climate observatory one mile north of the Fairgrounds reported 4.06 inches of rain. This caused some of the worst street flooding seen at the Fairgrounds. The bulk of the rain fell in a 3 1/2 hour period from 8:15pm to 11:45pm. The grandstand show was cancelled, and people had great difficulty trying to leave the Fair. The Twin Cities International Airport saw 7.28 inches from this event, second all-time only to the July 1987 "Superstorm" total of 10.00 inches. People driving on I-94 leaving the Fair found water "up to their hood ornaments" in low areas under bridges.

Fair forecast

So far the forecast for the opening weekend of the Fair looks summery. Highs will likely reach the upper 70s and 80s between Friday and Sunday. The weekend looks more humid with dew points climbing through the 60s. Isolated to scattered thunderstorm chances are possible this weekend.

Programming note: I will be live at the MPR booth on Judson at the Fair Tuesday, Aug. 30 between 3 and 6 p.m.. Please come by and say hello if you’re in the neighborhood!