Preliminary Climate Summary for May of 2025

Preliminary Climate Summary for May of 2025:

Mean monthly temperatures for May will be above normal for all locations in the state, but there are some differences. In southern counties, mean monthly temperature for May will be from 2°F to 3°F above normal, while some northern counties that enjoyed less cloudiness will report a mean monthly temperature that is 4°F to 5°F above normal. In the far north, places like International Falls and Baudette may be as much as 6°F to 7°F above normal. The mid-month heat that brought several 90°F plus days also set over 100 daily high temperature records, including 96°F at Baudette, International Falls, and Thief River Falls on the 11th, and 95°F at Red Lake Falls on the 12th. From May 11 to 14 International Falls (the nation’s Icebox) reported 4 consecutive days with temperatures of 90°F or higher, extremely unusual for them. Extremes for the month across Minnesota were 99°F at Crookston on the 13th, and 23°F at Ely on the 3rd.

Total rainfall for the month of May was mixed around the state, with generally less than normal values in the far north and far south, and above normal values elsewhere. Many areas of the state reported over 4 inches of rainfall for the month, and a few places like Hutchinson, Winsted, and Alexandria reported over 5 inches. In the far north, International Falls and Kabetogama reported less than an inch of rainfall for the month. Most of the rainfall for the month came over the 19th to the 22nd when over 30 new daily rainfall amounts were reported within the Minnesota climate station network. Some of those records included 2.00 inches of rain at Pipeston and 1.88 inches of rain at Litchfield both on the 20th, and 1.69 inches of rain at Red Wing on the 21st.

The rains in May helped to shrink the area of Minnesota reporting at least Moderate Drought. In mid-April over 41 percent of the state landscape was in at least Moderate Drought, but as of this week, that area is down to 15 percent. Most all of the major crops in the state were planted by the end of the 3rd week in May and will certainly take advantage of the stored soil moisture from the May rainfall.

The above normal windy days of March and April continued in May, but not quite as extreme. Places like Hibbing, St Cloud, Moorhead, International Falls, Duluth, and Brainerd all reported wind gusts of 30 mph or greater on at least a third of the days during the month. 

Weekly Weather Potpourri:

The BBC reported this week on the partial destruction of the Swiss village called Blatten in the Swiss Alps. The accelerated disintegration of the nearby Birch Glacier was the cause, as a large chunk of it broke away and smothered much of the village in mud and ice. Climate change has caused more rapid disintegration of this glacier in recent decades, and most of the village had been evacuated before this tragedy occurred.

Tropical Storm Alvin formed in the Eastern Pacific Ocean this week off the west coast of Mexico. It is the first named storm of the season. It may bring some unsettled weather to the southern tip of Baja California by Sunday, but it is expected to weaken into a tropical depression by then according to the NOAA National Hurricane Center.

MPR listener question:

I heard you and Cathy Wurzer talk about the natural air conditioning of the climate along the Lake Superior shoreline in northeastern Minnesota earlier this month when we were having all the 90°F days. It made me wonder, what is the highest maximum summer temperature at Grand Marais? 

Answer:

Climate records at Grand Marais go back to 1897. Believe it or note on August 7 of 1930 they measured an afternoon high temperature of 100°F, the only time that has happened there. Maximum temperatures of 90°F or higher are rare in Grand Marais and occur only once every 4 or 5 summers.

Twin Cities Almanac for May 30th:

The average MSP high temperature for this date is 74 degrees F (plus or minus 9 degrees F standard deviation), while the average low is 55 degrees F (plus or minus 7 degrees F standard deviation).

MSP Local Records for May 30th:

MSP records for this date: highest daily maximum temperature of 98 degrees F in 1934; lowest daily maximum temperature of 54 degrees F in 1922; lowest daily minimum temperature of 37 degrees F in 1947; highest daily minimum temperature of 69 degrees F in 1988; and record precipitation of 2.04 inches in 1877. There has not been any snowfall on this date.

Average dew point for May 30th is 51°F; the maximum dew point on this date is 72°F in 1918 and the minimum dew point on this date is 24 degrees F in 1964.

All-time state records for May 30th:

The state record high temperature for this date is 108 degrees F at Pipestone (Pipestone County) in 1934. The state record low temperature for this date is 20 degrees F at Pokegama Dam (Itasca County) in 1889. The state record precipitation for this date is 5.63 inches at Preston (Fillmore County) in 1980. The statewide snowfall record for this date is 3.0 inches at Tower (St Louis County) in 1897.

Past Weather:

The hottest May 30th was in 1934 when the afternoon temperature reached 100°F or higher in 30 Minnesota counties. It was one of the hottest days ever recorded in the month of May.

Widespread frost occurred across Minnesota on May 30 of 1947. Frost was reported as far south as Austin, while many northern communities reported morning low temperatures in the 20s F. The afternoon high temperature at Park Rapids only reached 50°F. Fortunately most crops were planted late that spring, so they were not vulnerable to frost damage.

Strong thunderstorms brought very heavy rains to portions of southern Minnesota over May 28-30 of 1980. Many areas reported 4 to 5 inches of rain which caused flash flooding and road closures. Areas around Winona and Lanesboro reported over 6 inches of rain, while Preston reported over 7 inches. Some crop fields were flooded and had to be replanted.

On May 30 of 1998 a derecho (straight line wind storm) moved across central Minnesota with 80 to 100 mph wind gusts. It caused damage in Carver, Dakota, Goodhue, Hennepin, McLeod, Ramsey, Scott, and Washington Counties. Especially hard hit was the neighborhood of Highland Park in St Paul where hundreds of homes were damaged, trees were uprooted, vehicles overturned, and power lines taken down. 

Outlook:

Sunny and warmer over the weekend, with above normal temperatures. Air quality may be of concern in some places due to smoke from the wildfires in Canada. Continued warm weather on Monday, but with a chance for showers and thunderstorms in the evening. Chances for showers and thunderstorms will persist on Tuesday and temperatures will cool closer to normal by Wednesday and Thursday, but with continued chances for showers.