June 2021 Saint Cloud Weather Summary

Warmest Overall June Since 1933 Worsens Rainfall Shortage

June 2021 Saint Cloud Weather Summary

After an up and down May, marked by a late month cool spell that nearly produced freezing temperatures in St. Cloud, Minnesota quickly felt the heat that has persisted in the Southwest all summer and has occasional pushed through the Northwest into southern Canada. St. Cloud had 7 consecutive days with a high of at least 90 degrees from June 4 through June 10. During that time, there were 10 daily record warm temperatures either set or tied. The hottest two days were June 4 (high of 97) and June 5 (high of 98). Those were as many high temperatures of 97 degrees or above as had occurred during the complete warm seasons of 2007 through 2020. The seven straight days with a high of at least 90 degrees was the earliest such streak in St. Cloud records and the longest heat wave (at least 3 straight days with a high of at least 90 degrees) since June 16-25, 2006. It was also the earliest recorded 7-day heat wave in St. Cloud records. Also, the record warm low of 74 degrees on June 6 was the earliest occurrence of a low temperature that warm in St. Cloud records.

There was only one really hot day the rest of June (95 degree high on June 13) and temperatures did decrease to near average the last week of the month. Still, that was enough to push the St. Cloud average June temperature to 71.4 degrees, 5.4 degrees warmer than average. That tied June 1931 for the 5th warmest June in St. Cloud records and the warmest June since 1933.

June 1988, even though it ranks 0.3 degree cooler than June 2021, was still more extreme than this past month. There were 11 days in June 1988 with a high of at least 90 degrees with 2 days over 100 degrees. The reason that June 1988 ranks lower is that the low temperatures were a bit cooler than in June 2021. That reflects that the summer of 1988 was in the middle of the last long-term extreme drought in the central US. June 1988 was not only hot, but there was also only 0.05 inch of rain, by far the driest June in St. Cloud records.

Rainfall was also a problem in June 2021. The St. Cloud Regional Airport picked up 2.63 inches of rain during the month, 1.12 inch below average. The combined May and June rainfall was only 4.93 inches, nearly two and a half inches below the average of 7.41 inches. Much of the rain came in a regime of daily scattered thunderstorms during the last week of June, which produced the first daily rainfall of at least one inch during 2021. However, these showers were highly localized. Even St. Cloud State University had a lot less rain (0.93 inch versus 2.11 inches at the Airport) and places to the northwest as close as St. Stephen and Holdingford had less than half an inch of rain during the week. While the St. Cloud Airport has seen nearly 5 inches of rain in May and June combined, the driest areas from north central to west central Minnesota have seen less than 2 inches of rain during the same period.

The lack of rainfall has produced worsening water shortfalls in especially western and central Minnesota. That has resulted in river flows in much of northern and central Minnesota to be in the lowest 25 percent with some areas showing flow in the lowest 10 percent. Still, most rivers are short of the record, usually set in 1988 or the 1930's. 70 to 75 percent of Minnesota soil moisture was rated as short or very short in moisture in the June 28 Minnesota Weekly Crop Report. The persistent drought conditions that began in winter in the Northern Rockies and North Dakota began spreading again into Minnesota and Iowa during June (set slider to difference between June 1 and June 29 on US Drought Monitor comparison page).

Really hot summers have been rare since the 1990's. While winters during the 1997 to early 2010's were frequently much warmer than average, the summer periods haven't been nearly as hot. 1988 has been the only summer later than 1936 which has rank among the 10 warmest summers. Since the 33 90-degree highs in 1988, only 8 of the 22 summers have seen an above average number of 90-degree highs, with the 20 recorded in both 2006 and 2007 being the highest. The 8 90-degree highs this June were the most in June since 1988 (11).

The trend of relatively cool summer high temperatures and elevated summer low temperatures were evident in the new 1991-2020 averages for St. Cloud. Average high temperatures during June, July and August each decreased by a few tenths of a degree. Howeve, the average low temperature in each summer month has increased with June having the biggest gain of 1.2 degrees. This reflects the more humid air, which makes it more difficult for low temperatures to drop as much.

The early outlook for July shows a piece of the devastating heat wave in Southwestern Canada and the Pacific Northwest moving in for a good chunk of the weekend. This will likely lead to the warmest high temperatures seen since early June.

    June 2021 Statistics