Some Perspectives on June Heat

Some Perspectives on June Heat:

On a statewide basis 14 of the past 20 Junes have been warmer than normal, four of them ranking among the 20 warmest in state history.

For the Twin Cities June usually brings 2-3 days with temperatures of 90 degrees F or greater. In some areas of northeastern Minnesota June rarely brings a 90 F day, while in western portions of the state 3-4 days of 90 F temperatures are common.

In the Twin Cities June Heat Waves of two-days duration or longer with a Heat Index Value of 95 degrees F or higher, occur about once every four years. The last prolonged June Heat Wave was in 2001 when Heat Index Values of 95 degrees F or greater were measure for five consecutive days. During June of 1931 there were 7 days with a Heat Index Value of 95 F or higher.

Though we have not seen 90 degrees F this month in the Twin Cities, looks like this Friday, Saturday and Sunday will be our first dose of June Heat with 90 F temperatures and dew points approaching 70 degrees F. Fortunately this heat will be short-lived as we will cool down sharply by Monday of next week.

Weekly Weather Potpourri:

This week NOAA offers a map depiction of SevereWeather Climatology across the country in terms of the historical frequencies of severe weather reports including high winds, hail, severe thunderstorms, and tornadoes.

The UK Meteorological Office provides some insights about what causes the allergy season to sometimes be so severe. They also describe the various pollen seasons and how they are working with the National Health Service to improve forecasts that relate to the pollen seasons.

This week it was reported that New Delhi, India has been experience a prolonged spell of serious air pollution, quite hazardous for transportation due to low visibility, and also for public health as many citizens there have taken to wearing masks. In some areas of the city, pollution has reached 30 times the maximum threshold recommended by the World Health Organization. In addition daily high temperatures have been between 103 degrees F and 110 degrees F.

MPR listener question:

Some of us at Nick’s Downtown Diner in Cannon Falls were remembering this week 6 years ago when we got nearly 9 inches of rain in less than 24-hours and the Cannon River subsequently hit an all-time flood crest. Then Duluth got a 10 inch rainfall the very next week. How many places in Minnesota have recorded 9 or more inches of rain in one day?

Answer:

There are not too many places considering we have nearly 150 years of climate records. Here are those relatively long-term climate stations that have:

Hokah (Houston County) August 19, 2007 15.10 inches
Altura (Winona County) August 19, 2007 11.45 inches
Fort Ripley (Crow Wing County) July 22, 1972 10.84 inches
Two Harbors (Lake County) June 20, 2012 10.45 inches
Duluth (St Louis County) June 19, 2012 (overnight) 10.00 inches
Bagley (Clearwater County) July20, 1909 10.00 inches
Isle (Mille Lacs County) July 22, 1972 9.80 inches
Milan (Chippewa County) July 4, 1995 9.78 inches
Amboy (Blue Earth County) September 23, 2010 9.48 inches
Bricelyn (Faribault County) September 14, 2004 9.22 inches
MSP (Hennepin County) July 23, 1987 9.15 inches
Fosston (Polk County) July 19, 1909 9.00 inches

Twin Cities Almanac for June 15th:

The average MSP high temperature for this date is 79 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 59 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for June 15th:

MSP weather records for this date include: highest daily maximum temperature of 94 degrees F in 1913; lowest daily maximum temperature of 61 degrees F in 1945: lowest daily minimum temperature is 41 degrees F in 1989; highest daily minimum temperature of 71 degrees F in 2007; record precipitation of 2.80 inches in 1874; and there has been no snow on this date.

Average dew point for June 15th is 54 degrees F, with a maximum of 73 degrees F in 1952 and a minimum of 32 degrees F in 1961.

All-time state records for June 15th:

The state record high temperature for this date is 106 degrees F at Lamberton (Redwood County) in 1979. The state record low temperature for this date is 24 degrees F at Meadowlands (St Louis County) in 1917. State record precipitation for this date is 8.83 inches at Cannon Falls (Goodhue County) in 2012; and no snow has fallen on this date in the state.

Past Weather Features:

Frost came to many northern parts of Minnesota on June 15, 1917. Over a dozen communities saw the thermometer drop into the 20s F overnight, and 25 counties reported frost. In some cases it was damaging to the wheat crop.

The hottest June 15th statewide was in 1979 when over a dozen communities reported a temperature of 100 degrees F or better. Most of the state was blanketed by 90 F temperatures, the cool spot being Two Harbors with 78 degrees F. In many areas the temperature never dropped below 70 degrees F overnight. The heat had little damaging effect on crops, as it was a late planting season and many crops were in the early stages of growth.

Intense thunderstorms brought massive flooding to portions of Goodhue, Rice, and Dakota Counties over June 14-15, 2012. Rainfall amounts of 5 to nearly 9 inches were reported. Many roads were closed and a record flood crest went down the Cannon River.

Outlook

Hot, sticky weekend coming up, especially south of the I94 corridor. Many will see high temperatures in the 90s F and warm nights in the 70s F. Chance for showers and thunderstorms as well, especially on Saturday night and early Sunday. Cooler on Monday and Tuesday, then warming a bit on Wednesday and Thursday.