Very Warm Start to May

Very Warm Start to May:

The month of May has started very warm across Minnesota, with temperatures averaging 4°F to 7°F above normal. Daytime high temperatures in the 80s F were reported on May 4, May 5, and May 6 from several areas of the state, the first time such temperatures have been measured since late last October. Even International Falls (the Nation’s Icebox0 reported back-to-back days in the 80s F over May 4-5.

A few locations reported some record-setting high daily maximum temperatures this week. Some examples:

On May 4th a new daily record high temperature was reported from Elk River with 81°F and from Baudette with 85°F.

On May 5th Kabetogama reported a record high temperature of 80°F.

On May 6th Grand Marais airport reported a record high of 81°F.

Despite the warm start to May, the morning of May 8th this week brought frost to many northern Minnesota communities. Portions of St Louis, Koochiching, and Lake Counties reported morning low temperatures ranging from 26°F to 32°F.

Most areas of the state have received less than normal rainfall so far this month, mostly in the range of 0.25 inches to 0.40 inches. A few places in northeastern Minnesota have reported over 1 inch of rain, and back on May 2nd places like Gunflint Lake, Orr, and Chisholm reported 0.2 to 0.3 inches of snow, probably the last of the season.

Corn planting in Minnesota is over half finished and soybean planting is over a third finished this week. Topsoil moisture conditions remain adequate to surplus in over 80 percent of the state. As crops germinate and emerge, farmers will hope for more rainfall. Late next week looks to bring more rainfall to the state, while temperatures are expected to average 10°F to 20°F above normal through mid-month.

Weekly Weather Potpourri:

An article in this week’s AGU-EOS Bulletin suggests that climate change likely played a role in the outbreak of South Korea’s worst wildfires during March of this year. Over 386 square miles were burned, and there were 32 deaths blamed on the fires. “The combination of high temperatures, low humidity, and high wind speeds that occurred from 22 to 26 March were unusual, even for today’s climate, the researchers found. Such conditions are expected to occur in March only once every 340 years. But this combination of conditions would have been even rarer in a pre-industrial climate, occurring only once every 744 years. The study suggests that the trend in the HDWI (Heat, Drought, Windiness Index) was driven primarily by unseasonably high temperatures.”

The UK Met Office reported this week that April was the sunniest in history across the United Kingdom as far back as records go to 1910. There were 47 percent more sunshine hours than average during April and many days were cloud-free. These conditions coupled with warm temperatures brought an early start to the gardening season.

A recent study in Nature Communications Earth and Environment documents that climate change has contributed to wildfire extent in western North America and higher mortality rates due to particulate matter in the atmosphere. The study covered the period from 2006 to 2020. The study finds that the indirect effects of climate change on human health through wildfire smoke will continue to escalate and become a much greater economic burden for states like California, Oregon, and Washington.

MPR listener question:

How many hail reports are filed each year in Minnesota and when is the peak time?

Answer:

Over the several decades the average is about 120-130 hail reports each year. One of the lowest annual reports was in the drought year of 1988 when there were only 49. On of the highest number of reports was in1998 with 412. The peak months for hail reports are May and June, representing about 50 percent of all annual occurrences. The peak date for hail frequency in Minnesota is June 1st, though in recent years we have had major hailstorms in August.

Twin Cities Almanac for May 9th:

The average MSP high temperature for this date is 67 degrees F (plus or minus 12 degrees F standard deviation), while the average low is 47 degrees F (plus or minus 8 degrees F standard deviation).

MSP Local Records for May 9th:

MSP records for this date: highest daily maximum temperature of 91 degrees F in 1987; lowest daily maximum temperature of 40 degrees F in 1924; lowest daily minimum temperature of 27 degrees F in 1966; highest daily minimum temperature of 69 degrees F in 1896, and record precipitation of 1.14 inches in 1918. Record snowfall is 0.4 inches also in 1924.

Average dew point for May 9th is 39°F; the maximum dew point on this date is 66°F in 1985 and the minimum dew point on this date is 10 degrees F in 1966.

All-time state records for May 9th:

The state record high temperature for this date is 99 degrees F at Milan (Chippewa County) in 1928 and at Pipestone (Pipestone County) in 1934. The state record low temperature for this date is 9 degrees F at Isabella (Lake County) in 1966. The state record precipitation for this date is 3.22 inches at St Cloud in 1979. The statewide snowfall record for this date is 8.6 inches at Island Lake, near Duluth in 2019.

Past Weather:

An early May Heat Wave brought record-setting high temperatures on May 9th in 1934. Over 20 Minnesota counties saw afternoon temperatures reach the 90s F. The overnight low temperature only went down to 76°F at St Peter. May of 1934 was the 2nd warmest in state history with many 90°F days.

The coldest May 9th was in 1966 when dozens of Minnesota climate stations reported record low temperatures, mostly in the teens and twenties. Frosts were reported in 85 of Minnesota’s 87 counties, and some newly emerged crops were killed.

Outlook:

Warm weekend coming up with temperatures well above normal. Many areas will see temperatures in the 90s F on Sunday afternoon. Temperatures will continue to run well above normal through Wednesday of next week, with breezy conditions and very low relative humidity. This weather will lead to a greater risk for wildfires. There will be a chance for showers and thunderstorms late Wednesday and into Thursday, followed by cooler temperatures, but still above normal for this time of year.