Preliminary Climate Summary for July 2021

Preliminary Climate Summary for July 2021:

July of 2021 will be remembered by Minnesotans for worsening drought, Heat Advisories, and frequent poor air quality due to smoke from Canadian wildfires.

Warm and dry are the two most appropriate climate words for July. Most climate stations reported a mean monthly temperature that was from 1°F to 4°F above normal. Combined with the near-record warm June, the June-July two month period in 2021 is the 3rd warmest in history on a statewide basis (only 1933 and 1988 were warmer). Extreme temperatures for July were 102°F at Granite Falls (Yellow Medicine County) on July 4th and just 32°F at Seagull Lake (Cook County) on July 8th.

Many areas saw 10 to 12 days with afternoon high temperatures of 90°F or greater. MSP Airport reported 10 such days, adding to the 12 recorded during June. The 22 days with 90°F or above at MSP for the months of June and July in 2021 rank 3rd historically (tied with 1894 and 2012). There were 30 such days in 1988 for the two-month period and 26 such days for the same period in 1933.

The National Weather Service had to issue many Heat Advisories and Excessive Heat Warnings during the month. July 28th brought the greatest Heat Index Values, ranging from 100°F to 117°F. There were many days with dew points in the 70s F, greatly inflating the Heat Index. MSP set a new daily high dew point record on July 28th with a reading of 79°F.

According to NOAA 39 daily maximum temperature records were set or tied within the Minnesota climate station network during the month, many in northern counties. In addition, another 25 daily warm minimum temperature records were set or tied.

Only a handful of climate stations in southeastern Minnesota record above normal rainfall during July (some in Wabasha, Houston, Winona, Faribault, and Olmsted Counties). Hokah topped the list with 6.22 inches. Most of the state reported below normal rainfall, and many climate stations reported less than 1 inch total, as well as just 5 or 6 days with measurable rain. Some of the lowest total rainfall numbers are listed below:
Red Lake Falls 0.23” (Driest July in History)
Grand Portage 0.50” (Driest July in History)
Hallock 0.64” (3rd Driest July in History)
Redwood Falls 0.71” (7th Driest July in History)
Thorhult 0.73” (2nd Driest July in History)
Mora 0.82” (2nd Driest July in History)
St Cloud 0.83” (6th Driest July in History)
MSP Airport 0.87” (8th Driest July in History)

The total at Red Lake Falls represents the driest July there historically (climate records since 1913). The half inch of rain at Grand Portage for the month also represents their driest July ever (records back to 1895). The July rainfall total at MSP is the lowest since 1982.

Combing the statewide average rainfall for July (about 1.90 inches) with the statewide average rainfall for June (about 1.80 inches) places the June-July two-month period as the 3rd driest in state history (surpassed only by 1910 and 1936).

Only 13 daily rainfall records were set or tied within the state climate network, the largest being 2.12 inches at Wabasha on July 7th. Many climate stations are now showing deficits of 7 to 10 inches below normal for the year so far.

During July of 2021 in Minnesota all measures and symptoms of drought worsened. To begin the month about 11 percent of the state was in Severe Drought, with no areas in Extreme Drought. By the end of the month 75 percent of the state was designated to be in at least Severe Drought and 22 percent in Extreme Drought. Lake levels and stream flows declined, fire risk increased, crop condition ratings fell, water restrictions were put into place and the State Drought Task Force began to meet.

In addition, the MPCA noted that some of the worst ever air quality was measured across the state due to the wildfires in Canada. July of 2021 will certainly be memorable in the history books for many negative impacts.

Weekly Weather Potpourri:

The BBC reports this week that portions of Turkey, Greece, and Italy are expected to see their Heat Wave continue with temperatures approaching 100°F in places next week. A static high-pressure system is dominate there.


Strong thunderstorms brought heavy rains, wind damage, and even a few tornadoes to portions of Wisconsin and Illinois on Thursday night, July 28th. Wind gusts over 60 and 70 mph were measured across Wisconsin and portions of northern Illinois. According to the Weather Underground there were also a number of power outages.


There is an interesting article in this week’s AGU-EOS Bulletin about climate litigation and the difficulty in tying individual weather events and climate episodes to increasing greenhouse gas emissions. Lawyers are getting better at presenting evidence, but it may be slow to evolve.

MPR listener question:

The extreme temperatures in the Pacific Northwest recently got me to thinking. Minnesotans are used to being the "icebox of the nation" in winter, but has there ever been a day when Minnesota reported the maximum temperature in the country? I'm thinking maybe during the 1936 drought, but that may be a stretch.

Answer:

Despite all the maximum temperature records set in Minnesota during July of 1936 to the best of my knowledge there were no reports of temperature from our state that represented the hottest temperature in the nation. Many other states were recording maximum temperatures from 114°F to 120°F that month.

But I do know that there is a date when Minnesota reported the highest Heat Index Value (calculated from temperature and dew point) in the nation. It was July 19, 2011 when between 3pm and 5pm in the afternoon Moorhead Municipal Airport reported a temperature of 95°F with a dew point of 88°F, and a Heat Index of 134°F!

Twin Cities Almanac for July 30th:

The average MSP high temperature for this date is 83 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 64 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for July 30th:

MSP records for this date: highest daily maximum temperature of 100 degrees F in 1933; lowest daily maximum temperature of 63 degrees F in 1956; lowest daily minimum temperature of 50 degrees F in 1971; highest daily minimum temperature of 79 degrees F in 2006; record precipitation of 1.65 inches in 1872. No snowfall has occurred on this date.

Average dew point for July 30th is 60°F; the maximum dew point on this date is 81°F in 1999; and the minimum dew point on this date is 35 degrees F in 1936.

All-time state records for July 30th:

The state record high temperature for this date is 107 degrees F at Milan (Chippewa County) in 1933. The state record low temperature for this date is 31 degrees F at Virginia (St Louis County) in 1984. The state record precipitation for this date is 4.84 inches at Dodge Center (Dodge County) in 1950. No snowfall on this date.

Past Weather Features:

July 30, 1964 brought a taste of autumn to portions of northern Minnesota as morning low temperatures dipped into the 30s F across portions of St Louis and Itasca Counties. Morning frost was reported from the Iron Range.

July 30, 1999 brought a hot and humid day to Minnesota with Heat Index Values ranging as high as 110°F to 120°F. It was a difficult 70 mile bike ride from New Prague to Hastings for the MS Tram riders, many of whom had to dropout because they could not stay hydrated. Faribault reported a record Heat Index of 123°F.

Outlook: 

A mostly sunny and dry spell of weather coming up, with near normal temperatures. Haze and smoke may continue in some areas. Getting warmer towards the end of next week with a chance for showers by Thursday.