Preliminary June Climate Summary:
From a temperature standpoint, June did not generate many anomalies in Minnesota. Average monthly temperature will be close to normal for most climate stations in the state. Extremes across the state ranged from 94°F at several locations on the 12th and again on the 24th, to just 29°F at Brimson (St Louis County on the morning of the 10th.
The real historical signature of this June climate will be the frequency and abundance of rainfall, which led to widespread flooding. Most climate stations reported rainfall on half of the days of the month, and some reported rainfall on up to 20 days. Total amounts of rainfall were well above normal for the month, and in many cases twice normal. Those geographic areas receiving the most surplus rainfall included northeastern counties, and all southern counties, especially those in south-central Minnesota. Within the statewide National Weather Service observer network over 70 new daily rainfall records were set, including 5.32 inches at Wolf Ridge (Lake County) on June 19th which was a new statewide record for the date.
The statewide average rainfall for June was over 6.25 inches, marking the 9th wettest June in state history (note this ranking may change with the addition of Friday and Saturdays rainfall). Dozens of climate stations reported their wettest June in history. Some examples:
Sherburn (Martin County) 12.36 inches
Wells (Faribault County) 13.20 inches
St James (Watonwan County) 12.61 inches
Windom (Cottonwood County) 13.70 inches
Faribault (Rice County) 16.63 inches
(Note: these numbers are likely to get higher before June 30th)
Across south-central counties in Minnesota the average June rainfall was close to a foot, marking the wettest June in history for those counties. A vast majority of rivers and streams were running at very high levels of volume, and many were above flood stage this week. The Mississippi River at La Crosse, WI set a new stage (flow volume) record for the month of June.
Wettest April-June in State History:
The widespread flooding was not entirely due to June rainfall. Soils became saturated in many areas of the state due to the persistent surplus rains in April and May as well, meaning that the June rainfall amounts generated a higher than normal amount of runoff. For the 91-day period (April-June) many climate stations reported half to two-thirds of the days brought at least a trace of rainfall, and there were many days that brought over one inch. The statewide average rainfall for the three months was over 15.30 inches breaking the previous state record of 15.28 inches back in 2014. Many climate stations reported over 20 inches of rainfall for this period. Some record-setting examples:
Winnebago (Faribault County) 25.56 inches
Sherburn (Martin County) 25.07 inches
Windom (Cottonwood County) 25.41 inches
Brownton (McLeod County) 23.02 inches
Faribault (Rice County) 23.02 inches
Waseca (Waseca County) 23.70 inches
Worthington (Nobles County) 25.31 inches
(Note: these numbers are likely to get higher before June 30th)
Prolonged drier than normal conditions would be welcome in many areas of the state as we enter the month of July.
July 4th climatology
For the Twin Cities area rain has occurred on this holiday 77 times since 1871 (about 50 percent of the time), the highest frequency of precipitation for all major holidays of the year. The longest streak of rainy Independence Days was eight consecutive years from 1900 to 1907, with July 4th, 1900 being the wettest ever as 2.27 inches of rain fell from a thunderstorm. The holiday was rainfree for six consecutive years from 1939 to 1944 and again from 1952 to 1957. It has rained on the most recent two July 4ths (2022 and 2023)..
In terms of temperature, the average high temperature for the date is 83°F and the average low 65° F. The average dew point is 59 F, but has been as high as 79 F (in 1999). The Heat Index (derived from temperature and humidity or dew point) has been uncomfortably high on the 4th of July a number of times. There have been seven July4th holidays when the Heat Indexvalue exceeded 100 F, most recently 2012 when it hit 108 degrees F. The worst case was a Heat Index of 110 F in 1949. This was the cause of 12 heat related fatalities that year. The coldest daytime temperature on July 4th was just 58 degrees F in 1967.
The outlook for this July 4th looks like temperatures from 75 to 80°F with a chance for showers and thunderstorms and moderate southwest winds.
Weekly Weather Potpourri:
The BBC reported this week that temperature conditions for the balance of the summer may be above normal inside the Arctic Circle as a result of the abundant wildfires going in the high latitudes, especially in Russia. More than 160 wildfires have been reported in Arctic Russia so far this summer. “Scientists are concerned that smoke from the flames will hinder the ability of the Arctic ice to reflect solar radiation - which would mean both the land and sea absorb more heat.”
A recent study published in Nature Geoscience reveals that climate models underestimate the meltwater volume from the ice shelves of Antarctica. The researchers analyzed data from the Landsat 8 satellite over the period 2013 to 2021 during the Southern Hemisphere summers when meltwater occupies the surface of these ice shelves and changes the albedo (reflection) from the surface. “we found that adjusting the surface albedo in a regional climate model to account for the lower albedo of surface meltwater resulted in 2.8 times greater snowmelt across five representative ice shelves.” This may lead to significant underestimates of ice shelf melting and ice shelf stability.
MPR listener question:
With all the relatively heavy rain that we’ve had in Minnesota in the last few weeks… are there models for the Mississippi River watershed that would predict or project the water levels along the Mississippi down to the Gulf of Mexico? How often are the run? And what are they predicting in the next few months?
Answer:
The NOAA North-Central River Forecast Center in Chanhassen, Minnesota is one of the offices with this responsibility. They do point-specific forecasts twice daily (12 hourly) of stage or volume flow for many of the major rivers in our region, including the Mississippi River. These forecasts take advantage of the daily climate reports (rainfall) from all the relevant watersheds as well as Quantified Precipitation Forecasts out to 7 days. Some of the points along the Mississippi River for which the forecasts apply are Hastings, Red Wing, Lake City, Wabasha, and Minnesota City. They also include points further downstream as well. Beyond 7 days into the future precipitation outlook models help determine categorical flow forecasts. The outlook models for July, August, and September favor drier than normal conditions along the Mississippi River basin generally.
Twin Cities Almanac for June 28th:
The average MSP high temperature for this date is 82 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 64 degrees F (plus or minus 7 degrees F standard deviation).
MSP Local Records for June 28th:
MSP records for this date: highest daily maximum temperature of 102 degrees F in 1931; lowest daily maximum temperature of 64 degrees F in 1923; lowest daily minimum temperature of 47 degrees F in 1924; highest daily minimum temperature of 82 degrees F in 1931, and record precipitation of 2.33 inches in 1920. No snowfall has occurred on this date.
Average dew point for June 28th is 59°F; the maximum dew point on this date is 77°F in 1996; and the minimum dew point on this date is 33 degrees F in 1925.
All-time state records for June 28th:
The state record high temperature for this date is 107 degrees F at Browns Valley (Traverse County) in 1988. The state record low temperature for this date is 25 degrees F at Brimson (St Louis County) in 1992. The state record precipitation for this date is 6.25 inches at West Union (Todd County) in 1941. There has been no snowfall on this date.
Past Weather:
1931 brought the hottest June 28th in state history when 30 Minnesota counties reported afternoon high temperatures of 100°F or greater. At some locations the nighttime low temperature never dipped below 80°F.
Strong thunderstorms brought 2 to 5 inches of rain to many southern and western Minnesota communities on June 28 of 1959. Such thunderstorms were common during that growing season of 1959.
Campers in northern Minnesota awoke to a chilly morning on June 28 of 1983. Many areas reported temperatures in the 30s F, and there were frosts Lake, Carleton, and St Louis Counties. Daytime high temperatures along the north shore of Lake Superior remained in the 50s F..
Outlook:
Sunny and breezy on Saturday with cooler than normal temperatures. Cool morning to start Sunday, with less wind, but with increasing cloudiness later in the day and a chance for showers. Good chance for widespread showers and thunderstorms on Monday and Tuesday with a warming trend to near normal temperatures. Chances for showers continue on Wednesday and Thursday with near normal temperatures.
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