Preliminary June Climate Summary

Preliminary June Climate Summary

With the exception of a few northeastern Minnesota counties, June was warmer than normal, ranging from 2 to 5 degrees F above normal. Extremes ranged from 99°F at Marshall (Lyon County) on June 6th (which may be surpassed today, June 29), to 30°F at Brimson (St Louis County) on June 5th. During this warm June, at least 32 daily high temperature records were broken or tied while 51 daily warm minimum temperature records were broken or tied within the state climate network. In addition a number of days brought Heat Index values ranging from 95 degrees F to 105 degrees F due to record or near record high dew points. On Friday, June 29 dew points ranged throughout the 70s F and produced Heat Index Values that ranged up to 110 degrees F, making for the hottest of days across southern Minnesota. On a statewide basis June of 2018 will rank among the warmest 10 historically. For the Twin Cities June 2018 will probably rank just outside the warmest 10 historically. Only three days during the month produced below normal temperatures.

Nearly all areas of Minnesota were wetter than normal during June, especially in southern counties, where many climate stations reported from 5 to 10 inches for the month. Some south-central and southwestern counties reported 10 to 13 inches of rain, topped by Lake Wilson (Murray County) with 13.09 inches. For observers in St James, Amboy, and New Ulm it was the wettest June in their historical records. Over 50 daily rainfall records were broken or tied within the state climate network.

Weekly Weather Potpourri

During the Northern Hemisphere growing season various satellite images are available online to assess the vegetative health (both crops and native vegetation) for many areas of the world. These can be found online and NOAA provides a descriptive guide for doing so.

The BBC Weather Centre reported that many parts of Greece were plagued by heavy thunderstorms this week that delivered 4-6 inches of rainfall, causing widespread flash flooding and road closures. It was expected to continue raining there throughout most of the coming weekend.

New research from the University of North Carolina using detailed satellite imagery shows that the surface area of rivers and streams across the globe is about 45 percent greater than previously estimated. This information is significant in light of understanding the hydrologic cycle and potential impacts of climate change.

MPR listener question:

“In today’s world of rampant disinformation and lies, all hope was lost when Mark Seely, of all people, on public radio (Friday morning June 22nd) characterized the summer solstice as the beginning of astronomical summer when he knows full well that it is precisely the center of astronomical summer in the same way that the center of meteorological summer comes in the middle of July."..............Spider John Koerner (blues musician)

Answer:

Hello John. I hope my commentaries don’t give you the blues. I was correct last week when I referred to June 21, the summer solstice as the beginning of summer for the Northern Hemisphere. Commonly in meteorology and climatology we use the meteorological seasons (Dec-Feb is winter, Mar-May is spring, Jun-Aug is summer, and Sep-Nov is autumn). The astronomical seasons, which have been acknowledged by multiple countries and cultures for a much longer time period, do indeed use the positions of the sun over the equator, the Tropic of Cancer (Northern Hemisphere) and Tropic of Capricorn (Southern Hemisphere) as the markers for the start of each season. Please find below the precise definitions for the astronomical and meteorological season.
Astronomical Seasons

The astronomical definition uses the dates of equinoxes and solstices to mark the beginning and end of the seasons:
Spring begins on the spring equinox;
Summer begins on the summer solstice;
Fall (autumn) begins on the fall equinox; and
Winter begins on the winter solstice.

The beginning of each season marks the end of the last.

Because the timings of the equinoxes and solstices change each year, it follows that the length of astronomical seasons within a year and between years also vary.
Northern Meteorological Seasons

According to the meteorological definition, the seasons begin on the first day of the months that include the equinoxes and solstices:
Spring runs from March 1 to May 31;
Summer runs from June 1 to August 31;
Fall (autumn) runs from September 1 to November 30; and
Winter runs from December 1 to February 28 (February 29 in a leap year).

Twin Cities Almanac for June 29th

The average MSP high temperature for this date is 83 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 63 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for June 29th:

MSP records for this date include: highest daily maximum temperature of 102 degrees F in 1931; lowest daily maximum temperature of 64 degree F in 1959; lowest daily minimum temperature of 47 degrees F in 1924; highest daily minimum temperature of 83 degrees F in 1931; record precipitation of 3.48 inches in 1877. No snowfall has occurred on this date.

Average dew point for June 29th is 58°F; the maximum dew point on this date is 77°F in 2002; and the minimum dew point on this date is 38°F in 2010.

All-time state records for June 29th:

The all-time state high temperature for today's date is 110 degrees F at Canby (Yellow Medicine County) in 1931; the all-time state low for today's date is 27 degrees F at Pine River (Cass County) in 1925. The all-time state record precipitation for this date is 6.37 inches at Worthington (Nobles County) in 1969. No snowfall has been reported on this date.

Past Weather Features:

The hottest June 29th in state history was in 1931 when over 45 communities reported afternoon high temperatures of 100 degrees F or greater. It was 103°F at Little Fork, just outside of International Falls. The overnight temperature never dropped below 83 degrees F at Canby and Winona.

Over June 28-29, 1997 a band of heavy thunderstorms dropped 4-6 inches of rain across portions of Kandiyohi, McLeod, Sibley, and Meeker Counties. Widespread flash flooding and many road closures occurred in those counties.

June 29, 2000 brought frost to parts of northeastern Minnesota as temperatures fell below 32°F at Embarrass, Tower, and Kelliher. The next day temperatures were back in to the 70s F.

Outlook:

Hot on Saturday with chances for thunderstorms, especially in the southern counties. Continued chances for thunderstorms on Sunday and Monday, but with temperatures a bit closer to normal. Then returning to above normal temperatures for Tuesday through Thursday of next week.