Record Cold Prevails This Week in Minnesota:

The passage of a strong cold front across the state on Labor Day (September 7) not only brought widespread rainfall to many areas, but it produced a dramatic drop in temperatures as well, accompanied by strong winds. Cloud cover, winds, and a warm ground kept overnight temperatures from setting too many records, but daytime temperatures were held down to near record or record cold levels this week over September 7-9. Some of the records set for cold daytime maximum temperatures included:

September 7: 52°F at Lakefield (Jackson County); and 55°F at Brainerd (Crow Wing County)

September 8: Over 100 climate stations set records for cold daytime maximum temperature.
Among these were long term climate stations like:

49°F at Rochester and Artichoke Lake (Big Stone County)
50°F at Canby, Redwood Falls, and Park Rapids
51°F at Marshall
52°F at MSP, Wheaton, Pokegama Dam, Leech Lake, Cass Lake, Ada, and Brainerd
53°F at Pipestone, Gaylord, Milan, Alexandria, and Long Prairie
54°F at Collegeville
55°F at Rosemount
56°F at Waseca
57°F at Windom

September 9th brought dozens of more record cold maximum temperatures as well, including:
44°F at Worthington
45°F at Pipestone
46°F at Austin
47°F at Albert Lea, Marshall, and Rochester
48°F at Canby and Lamberton
49°F at Windom, Wheaton, and Redwood Falls
50°F at MSP, Cass Lake, and Caledonia
51°F at St Cloud and Morris
52°F at Winona and La Crescent

Clear skies and less wind allowed some Minnesota climate stations to set or tied daily minimum temperature records on September 9th and 10th:

For September 9th the following long-term climate stations reported record lows:
28°F at Thorhult and Floodwood
29°F at Park Rapids
30°F at Cass Lake
32°F at Brainerd
33°F at St Cloud
35°F at Wheaton

For September 10th the following long-term climate stations reported record lows:
27°F at Cotton and Babbitt
29°F at Kabetogama
30°F at St Cloud and Floodwood
33°F at Browns Valley
34°F at Redwood Falls and Litchfield

Many of these temperature readings were 20 to 25 degrees F colder than normal. The absolute coldest temperature this week was a morning low of 25°F at Brimson (St Louis County) on the 9th and that was a new record low there as well.

Weekly Weather Potpourri:

NOAA reported this week that La Nina conditions (colder than normal phase of the equatorial Pacific Ocean surface waters) were present during August, and there is a 75 percent chance they will persist through the coming Northern Hemisphere winter. This translates to a higher risk of a colder than normal winter for Minnesota.


Thunderstorms brought record heavy rains to the Washington, D.C. area on Thursday September 10th. The Washington Post reported that some areas of the District received 2 to 6 inches of rainfall in just a few hours bring flash floods and closed roadways. Washington National Airport reported a record 2.88 inches.


A paper recently published in the journal Science reveals a geologically reconstructed picture of Earth’s climate over the past 66 million years. One of the author’s states that "now that we have succeeded in capturing the natural climate variability, we can see that the projected anthropogenic warming will be much greater than that." Earth may warm to a level not seen in 50 million years should we not find ways to mitigate the pace of climate change. Science Daily reports in detail on this study.

MPR listener question:

I work at the information desk at the Mayo Clinic in Rochester, MN. On Tuesday and Wednesday this week we had daytime high temperatures that remained in the 40s F and patients were complaining of the Wind Chill. Can you tell me what has been the coldest daytime high temperature in Rochester during early September? Did we set any records this week?

Answer:

Indeed the daytime high temperature of just 47°F at Rochester on Wednesday (September 9) not only set a new record cold for the date, but that is the coldest daytime high temperature ever measured during the first ten days of September (going back to 1886) BTW the coldest daytime maximum temperature in Rochester for the entire month of September was 34°F on September 29, 1945

Twin Cities Almanac for September 11th:

The average MSP high temperature for this date is 74 degrees F (plus or minus 10 degrees F standard deviation), while the average low is 55 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for September 11th:


MSP 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 of 35 degrees F in 1962; highest daily minimum temperature of 75 degrees F in 1931; record precipitation of 3.11 inches in 1900. No snowfall has been reported on this date.

Average dew point for September 11th is 52°F; the maximum dew point on this date is 72°F in 2000; and the minimum dew point on this date is 25°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. The state record precipitation for this date is 5.50 inches at Pleasant Mound (Blue Earth County) in 1900. No snowfall has been reported on this date.

Past Weather Features:

By far the hottest ever September 11th was in 1931 when every place in the state saw afternoon temperatures climb into the 90s F, except for Two Harbors, Moose Lake, and Grand Marais. Ten climate stations hit the century mark in temperature.

A hard freeze in the north and widespread frosts in the central and southern counties were in the weather headlines for September 11, 1955. The growing season across Minnesota abruptly ended. Temperatures were as low as 22-26 degrees F in the Red River Valley of northwestern Minnesota.

This past Tuesday marked the 120th anniversary of the most lethal hurricane disaster in U.S. history. Galveston, TX was hit by 120 mph winds and a 20 foot storm surge on September 8, 1900. More than 6,000 people drowned and over 3600 homes were destroyed. This hurricane tracked north over Texas and the southern plains to merge with a cold front over Iowa by September 10th. The storm then produced a period of very heavy rains over Minnesota. In fact, the record Twin Cities rainfall for today's date of 3.11 inches is a direct result of this storm. Other parts of southern Minnesota reported 4 to 6 inches of rainfall as a result of this storm.

Outlook:

Following a cloudy, rainy, and somewhat cool Saturday, near normal conditions will return on Sunday with warming temperatures and sunny skies. Further most of next week will be dry with temperatures a few degrees warmer than normal.