Skip to main content

Last gasp for summer September 11th?

Last gasp for summer September 11th?

Strong south winds ushered in some very hot air across much of the state on Tuesday, September 11th. Many observers reported afternoon temperatures reaching into the 90s F, and in some locations new record high temperatures were set, including:

99 degrees F at Madison, 97 degrees F at Marshall, Owatonna, and Mankato, 96 degrees F at St Cloud, Lamberton, and Sioux Falls (SD), 95 degrees F at Luverne, and 94 degrees F at Waseca (tied record from 1948). MSP Airport reported 95 degrees F, just 1 degree F shy of the record for September 11th, and the first time a temperature that high has been recorded so late in September since 1939. A cold front caused temperatures to drop by 30-40 degrees F on Wednesday (Sept 12). At Madison in Lac Qui Parle County, the temperature fell from 99 degrees F at 3:30 pm on the 11th to 59 degrees F at 3:30 am on the morning of the 12th. On the St Paul Campus temperatures fell by 36 degrees F in less than 12 hours.

Small dose of rain

September 12th brought some much needed rainfall, albeit generally light, to parts of southern Minnesota. Those getting more than a quarter of an inch included: Preston (.45), Luverne (.45), Austin (.50), Caledonia (.75), La Crescent (.55), Spring Grove (.65), Harmony (.70), and La Crescent (.44). Much more rainfall is needed to recharge soils in most of the state, as the US Drought Monitor update released on September 12th still shows all or portions of 37 Minnesota counties to be in severe or extreme drought. You can read more about this here.

Coldest of the season up north

On Friday morning, September 14th the coldest temperatures of the fall season so far prevailed in northern communities. Both Grand Forks, ND and Tower, MN reported 29 degrees F, while Waskish, International Falls, Hibbing, Cook, Crane Lake, Bigfork, and Babbitt reported lows of just 28 degrees F. Embarrass, MN fell to 26 degrees F, coldest in the state. A warm up is seen for the weekend before another round of cold temperatures intrudes on Monday and Tuesday of next week.

Weekly Weather potpourri

A national drought perspective was provided this week by Brad Rippey of the USDA World Agricultural Outlook Board, highlighting the major features of the USA drought. Excerpts include:
Crops and cattle in drought have begun to rise again. Overall, drought has shifted toward the north and west in recent weeks.

- U.S. corn in drought stands at 84%, up a percentage point from a week ago. The corn harvest is underway, 15% complete nationally by September 9.
- Soybeans in drought also rose a point – to 81%. The soybean harvest is underway in a few areas, 4% complete nationally by September 9.
- Hay in drought rose 3 points to 66%, tying the high set on July 17 and 24.
- Cattle in drought reached a new high, rising 2 points to 74%.
- Winter wheat in drought is added this week, as planting is underway (4% complete). Nearly three-quarters (74%) of the winter wheat area is in drought.
- Due to expansion of drought in the nation’s mid-section, contiguous U.S. drought coverage reached a record-high 64.16% on September 11. The former record of 63.86% had been set on July 24.

The World Meteorological Organization (WMO) in Geneva, Switzerland issued a news release this week which invalidates the former world record high temperature reading of 136.4 degrees F from El Azizia, Libya (southwest of Tripoli) on September 13, 1922. The WMO Commission on Climate Extremes thoroughly investigated the record and found a number of concerns, including problematic instrumentation, observation site that was over a paved surface, and poor matching to surrounding measurements. With this declared invalidation, Furnace Creek in Death Valley now holds the world record high temperature with 134 degrees F, measured on July 10, 1913. On July 11 this past summer Death Valley reported a high of 128 degrees F, with an overnight low of 98 degrees F.

Dr. Nir Krakauer of City College of New York published a recent study to show that the Plant Hardiness Zones in the USA are shifting with climate change. His work suggests that the Plant Hardiness Zones released by the USDA earlier this year are really out of date as climate continues to change and winters become milder. You can read about his analysis here.

September is National Preparedness Month and there are many resources available at the FEMA website to assess your community's ability to deal with emergencies. You can get involved in regional discussions about disaster preparedness, read about building a supply kit for emergencies, join the national preparedness coalition, or get recommendations for developing a business emergency plan.

Super Typhoon Sanba in the Western Pacific Ocean was gathering strength this week and heading towards southern Japan and eventually South Korea. It packed winds of 165 mph with higher gusts and it was producing wave heights over 50 feet. It is expected to bring very heavy rains and high winds to Kadena, in southern Japan by the weekend.

MPR listener question

A number of people have recently asked whether we recorded above normal sunshine during the 2012 summer season in Minnesota.

Answer: The answer to this question is yes. Based on June-August sky conditions reported from MSP Airport, there were 11 percent more clear sky days, 39 percent more partly cloudy days, and close to 80 percent less totally cloudy days. In addition, the measurements of solar radiation (total solar energy) from the University of Minnesota Research and Outreach Center at Waseca show 11 percent more solar radiation than average in June, 6 percent more than average in July, and 7 percent more than average in August. Of course there is a historical correlation between drought and more sunshine, and that was evident this year.

Twin Cities Almanac for September 14th

The average MSP high temperature for this date is 71 degrees F (plus or minus 9 degrees F standard deviation), while the average low is 52 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for September 14th

MSP weather records for this date include: highest daily maximum temperature of 98 degrees F in 1939 lowest daily maximum temperature of 48 degrees F in 1903; lowest daily minimum temperature of 33 F in 1996; highest daily minimum temperature of 74 F in 1939; and record precipitation of 1.60 inches in 1994.
Average dew point for September 14th is 47 degrees F, with a maximum of 73 degrees F in 1994 and a minimum of 25 degrees F in 2011.

All-time state records for September 14th

The state record high temperature for this date is 103 degrees F at Redwood Falls (Redwood County) in 1939. The state record low temperature for this date is 18 degrees F at Cook (St Louis County) in 1964. State record precipitation for this date is 9.22 inches at Bricelyn (Faribault County) in 2004; and the state record snowfall for this date is 0.3 inches at International Falls (Koochiching County) in 1964.

Past Weather Features:

Light frost was reported in the Twin Cities area on September 14, 1873. The official temperature dropped to 35 degrees F. It was the first of 9 nights when the temperature fell into the 30s F during September, one of the coldest in state history.

A trace of snowfall was measured in both Minneapolis and St Paul back on September 15, 1916. It was the start of the worst snow season in the Twin Cities since that of 1880-1881 (estimated 110 inches in St Paul). Twin Cities snowfall for 1916-1917 totaled 84.9 inches. In fact, statewide it turned out to be a very challenging winter, with nearly 82 inches of snowfall at Duluth and 99 inches at Stillwater.

September 14, 1923 brought a killing frost to Minnesota, with a number of observers reporting morning lows in the 20s F. Campbell, New Ulm, and Zumbrota all reported temperatures in the 20s F as the growing season came to an abrupt end.

An autumn Heat Wave had a grip on the state over September 13-15, 1939, as most observers reported temperatures in the 90s F. New Ulm, St Peter, and Tracy reached 100 degrees F. Fortunately a strong cold front ended the hot spell of weather on the 16th, dropping temperatures by 25-20 degrees F.

An F-2 tornado (winds 113-157 mph) touched down about 3:45 pm on September 14, 1941 near Gilman in Benton County. It was on the ground for 8 miles and torn the roof off many homes. it also destroyed barns and out buildings on at least three farms.

On September 14-15, 2004 a stalled frontal boundary over southern Minnesota produced a series of thunderstorms which created widespread flash flooding in Martin, Faribault, Freeborn, Mower, and Dodge Counties. In those areas from 8 to 13 inches of rainfall was received over a 36 hour period. There were many mudslides and road closures in one of the largest flash flood events in state history.


Warmer over the weekend with highs from the lower 70s to lower 80s F. Increasing clouds late Sunday and a chance for showers and thunderstorms into Monday, then cooler for Tuesday and Wednesday next week. There will be another chance for rainfall by late next week.
Print Friendly and PDF