Wet start to September for some parts of Minnesota:
The first ten days of September have brought a month's worth of rainfall and more for many locations in Minnesota. The monthly normal rainfall for September ranges from 2.50 inches to 3.50 inches for most Minnesota climate stations. Through the first 10 days of this month over 40 climate stations already report rainfall amounts within that range. Brimson, Eveleth, Floodwood, Two Harbors, and Waseca have already reported over 4 inches of rain for the month, while Cotton and Keewatin have reported over 5 inches.
On a few days several observers reported significant thunderstorm rainfalls, in some cases establishing new daily record rainfalls. Some of these record values included:
September 2; 2.69 inches at Tracy
September 3; 1.98 inches at Cotton
September 5;2.02 inches at Lake Winnibigoshish
September 6;1.89 inches at Backus, 3.15 inches at Brimson, 3.70 inches at Cotton, 2.51 inches at Fergus Falls, 3.12 inches at New York Mills, 3.38 inches at Ottertail, 3.33 inches at Aitkin, 2.86 inches at Hill City, 2.77 inches at McGregor, and 2.51 inches at Sandy Lake Dam.
September 8; 2.68 inches at Wykoff, 2.33 inches at Cannon Falls, and 1.59 inches at Bricelyn
Worth further noting is that the National Weather Service outlooks for the rest of September favor continued above normal precipitation across Minnesota.
Seven Days of 70°F Plus Dew Points:
An unusually long run of hot, humid weather finally came to an end on Labor Day this week (August 31-September 6). Many areas of the state, including the Twin Cities recorded 7 consecutive days with dew point readings in the 70s F and Heat Index Values ranging from the upper 80s F to over 100°F. It was the warmest long spell of weather for the 2015 growing season and the most consecutive days with dew points in the 70s F for so late in the season. No dew point reports reached the 80s F but a number of climate stations saw dew point values as high as 77°F. Montevideo reported a Heat Index reading of 102°F on September 4th. More analysis on the spell of high dew points can be found at the MN State Climatology Office web site.
A cool, Canadian air mass that swept over the state on Labor Day caused the dew points to drop from the low 70s F on Sunday night to the low 50s F by Monday morning. This felt like natural air conditioning to most Minnesota citizens.
Community climate discussion at Owatonna, September 15th:Next week I will be visiting Owatonna for a meeting about climate change and its impacts on Minnesota communities. The meeting will take place at Camp Pillsbury, 315 S Grove Ave, Owatonna, MN 55060 on Tuesday, September 15 starting at 5:30pm. Owatonna Mayor Thomas Kuntz will also speak. You can find out more about this meeting and how to attend by visiting the Climate Generation web site or the University of Minnesota Extension’s Regional Sustainable Development Partnerships web site.
Weekly Weather Potpourri:
Typhoon Etau struck Japan on Wednesday (September 9) this week bringing high seas, strong winds, and heavy rains. Some areas received over 2 feet of rain and there was widespread flooding in many areas with disruptions to all forms of transportation. Thousands were evacuated from their homes due to flooding. Tropical Storm Kilo may affect northern parts of the country with rain as well early this weekend. You can read more at Japan Today or the Weather Channel web sites.
MPR Listener Question:
Twin Cities Almanac for September 11th:
MSP Local Records for September 11th:
MSP weather records for this date include: highest daily maximum temperature of 96 degrees F in 1931; lowest daily maximum temperature of 51 degrees F in 1924: lowest daily minimum temperature is 35 degrees F in 1962; highest daily minimum temperature of 75°F in 1931; record precipitation of 3.11 inches 1911; and no snowfall has been recorded on this date.
Average dew point for September 11th is 52 degrees F, with a maximum of 72 degrees F in 2000 and a minimum of 25 degrees F in 1955.
All-Time State Records for September 11th:The state record high temperature for this date is 111 degrees F at Beardsley (Big Stone County) in 1931. The state record low temperature for this date is 22 degrees F at Ada (Norman County) in 1955. State record precipitation for this date is 5.50 inches at Pleasant Mound (Blue Earth County) in 1900; and there has not been any snowfall on this date.
Past Weather Features:
The September Heat Wave of 1931 (from the 8th to the 13th) brought by far the warmest September 11th in state history. Except for Grand Marais Harbor on Lake Superior, every spot in the state saw temperatures reach into the 90s F, and ten communities reached an afternoon high of 100°F or greater, including Beardsley which reported 111°F the highest reading ever reported during September in Minnesota.
By far the coldest September 11th in state history was in 1955 when a killing frost ended the growing season early for many farmers. Morning lows fell into the 20s F in many areas of the state. In southern Minnesota residents of Preston, Waseca, and Austin saw the thermometer drop to just 29°F.