June Climate Summary

June Climate Summary:

June was uniformly warmer than normal across the state, breaking the cooler trend that dominated most of the first 5 months of the year. Average monthly temperatures ranged from 1°F to 4°F across the state. A few places in the far north like International Falls reported a mean monthly temperature that was very close to normal.

Extremes for the month ranged from 102°F at St James (Watonwan County), Sabin (Clay County), and Crookston (Polk County) on June 20th to 29°F at Celina (St Louis County) on June 5th. The reading at Celina was the coldest in the nation for that date. With the warmer than normal temperatures on most days, there were 91 daily record high maximum temperatures reported in the Minnesota climate station network, and 98 daily record warm minimum temperatures reported (several nights in the 70s F). Interestingly enough, on June 5th, Grand Marais reported a daily high of only 47°F which was a record cold maximum temperature for the date.

As for June rainfall around the state, reports were highly variable. Most climate observers reported less than normal rainfall for the month, with many reporting less than 1 inch. Some of these included:
0.58 inches at Kimball (Stearns County)
0.66 inches at Downtown St Paul Airport (Holman Field)
0.68 inches at Browns Valley (Traverse County)
0.87 inches at Redwood Falls (Redwood County)

The readings at Kimball and Downtown St Paul are the lowest June rainfall in their climate record, while the rainfall total at Redwood Falls is the 2nd driest June in their climate record, and the total at Browns Valley is the 4th driest June for them.

Conversely, a number of places reported a wetter than normal June, mostly thanks to some heavy thunderstorms. Climate stations in Houston, Otter Tail, Stearns, and Crow Wing Counties reported over 7 inches of rainfall for the month, while a number of others reported over 6 inches. Thunderstorms produced 20 new daily record rainfalls reported in the Minnesota climate station network, including 4.76 inches at Ottertail on June 25th.

Thanks to over 85 percent of the state reporting adequate to surplus soil moisture and above normal temperatures, crop growth progressed well during the month in most places. Inadequate rainfall caused the US Drought Monitor to place portions of Freeborn and Faribault Counties in south-central Minnesota into the Moderate Drought category.

Like earlier months of the year, June was windy. Many climate stations reported higher than normal wind speeds, with half of the days during the month showing wind gusts of 30 mph or greater, and some days over 50 mph.

Following the very high incidence of severe weather reports during May, there was little let up in June across the state. Over six dates (June 12, 14, 20, 23, and 25) the NOAA Storm Prediction Center received reports of 9 tornadoes in Minnesota, along with 86 reports of large hail, and 154 reports of damaging winds. Most of these were in northern and central counties.

The Minnesota DNR State Climatology Office offered many detailed commentaries and analyses of these storms on their web site.

Weekly Weather Potpourri:

This week’s AGU-EOS Bulletin features an article about air pollution in China. Efforts in recent years to mitigate air pollution in China have been successful to some extent, but the measured levels of fine particulates in the atmosphere are still up to 7 times greater than the healthy guidelines recommended by the World Health Organization.


The BBC reported this week that a widespread June Heat Wave in Western Europe broke many temperature records. Banak, Norway reported a daily maximum temperature of 91°F on June 29th, setting a record for the highest temperature ever recorded inside the Arctic Circle over Western Europe. Poland, Germany, Croatia, and Slovenia also reported several new high temperature records. In Tunisia of North Africa a record daily high temperature of 120°F was reported.

MPR listener question:

I live in Woodbury and it seems like many storms that come from the west or northwest, tend to dissipate when they get to the Twin Cities and then reform east of the St. Croix River in Western Wisconsin. I am wondering if the “Heat Island” of the Twin Cities causes these storms to scatter or dissipate? Or, is there some other natural phenomena that is occurring?

Answer:

Over the last 5 decades or so many atmospheric and climate scientists have studied to rainfall patterns associated with storms that pass across large urban areas. Many names come to mind, including Marshall Shepherd, Stan Changnon, Floyd Huff, Julie Winkler, and Roger Pielke Sr. These studies all found that the low-level inflow into thunderstorms that pass over urban areas is broken up or disrupted by the structural composition of the landscape (called surface roughness), and further the inflow of air does not contain as much water vapor as the surrounding landscape where the thunderstorms may have formed. As a result, the thunderstorm cells may dissipate or lose continuity. Then on the downwind side of the urban area, the surface inflow may converge, strengthen, and become more uniform again causing the thunderstorm rainfall to intensify. These dynamics are likely in play concerning some of your observations of recent Twin Cities rainfall patterns. Scale is a factor here as well. In large, complex thunderstorm systems the disruption caused by urban areas can be of little significance.

Twin Cities Almanac for July 1st:

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 65 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for July 1st:

MSP records for this date: highest daily maximum temperature of 100 degrees F in 1883; lowest daily maximum temperature of 60 degrees F in 1945; lowest daily minimum temperature of 46 degrees F in 1995; highest daily minimum temperature of 80 degrees F in 2002; record precipitation of 2.85 inches in 1997. No snow has been reported on this date.

Average dew point for July 1st is 58°F; the maximum dew point on this date is 78°F in 1916; and the minimum dew point on this date is 34 degrees F in 2001.

All-time state records for July 1st:

The state record high temperature for this date is 103 degrees F at Fergus Falls (Otter Tail County) in 1921. The state record low temperature for this date is 30 degrees F at Brimson (St Louis County) in 1988. The state record precipitation for this date is 8.00 inches at Theilman (Wabasha County) in 1978. No measurable snowfall has occurred on this date.

Past Weather Features:

July 1, 1911 brought temperatures of 90°F to 100°F to practically every corner of Minnesota. Seven counties reported temperatures of 100°F or greater. Overnight lows only dropped into the upper 70s F to low 80s F in many places. Two Harbors was the cool spot in the state with an afternoon high of 69°F.

On the morning of July 1, 1969 many Minnesota campers woke up to morning temperatures in the 30s F. There were frosts reported in Itasca, Cass, Becker, and St Louis Counties. The daily high only reached 60°F at Grand Marais.

Strong thunderstorms brought heavy rains to portions of southeastern Minnesota over July 1-2 of 1978. Many areas reported 4 to 7 inches of rain, while portions of Wabasha and Goodhue Counties reported over 9 inches. The Zumbro River flooded Rochester and other communities.

Outlook: 

Cooler on Saturday with temperatures near or slightly below normal. Chance for scattered showers and thunderstorms. Warmer for Sunday through Tuesday with a continued chance for widely scattered showers and thunderstorms. Then somewhat cooler for Tuesday through Thursday. Temperatures will warm up towards the end of next week.