University of Minnesota Extension
Menu Menu

Extension > Minnesota WeatherTalk > July 2014

Friday, July 18, 2014

Record Cool Spell for Mid-July: July 18, 2014 Commentary

In this edition of WeatherTalk

  • Record cool spell for mid-July 
  • New Seasonal Climate Outlook
  • Anniversary week for Minnesota's top rain storm
  • Weekly Weather potpourri
  • MPR listener question
  • Almanac for July 18th
  • Past weather 
  • Outlook

Record cool spell for mid-July

On Monday, July 14 a cold air mass from Canada invaded the state and brought record-setting cold high temperatures to scores of communities. Winds were strong from the north and remained so throughout much of the day and the night, so no overnight minimum temperature records were set. But the cooler, drier air from the north held down daytime temperatures into the 50s and 60s F across the state. Some observers reporting new record cold highs for the date included: 57 degrees F at Silver Bay, Isabella, Bigfork, and Embarrass; 59 degrees F at Crane Lake, Cloquet, and Ely; 60 degrees F at International Falls, Brimson, Leech Lake and Mora (tied with 1960); 61 degrees F at Moose Lake, Grand Rapids, and Bemidji (tied with 1961); 62 degrees F at Park Rapids; 63 degrees F at Moorhead, Alexandria, and Waskish (tied with 1994); 64 degrees F at Brainerd, Wheaton, Dodge Center, and Detroit Lakes; 65 degrees F at MSP, St Cloud, Baudette, Preston, and Waseca. High wind gusts over 30 mph were prevalent with the cold air advection at places like St Cloud, Warroad, Alexandria, Grand Rapids, and even the Twin Cities.

The cold air took residence for about 48 hours and brought new record cold mean daily temperatures (average of the maximum and minimum values for the day) to many communities on Tuesday, July 15th. Some of these records include: 55 F at Pipestone; 57 F at Windom; 58 F at Waseca and Grand Meadow; 59 F at Zumbrota, Austin, and Winnebago; and 60 F at Rochester.

Finally, clear skies, high pressure, and calm winds brought some record minimum temperature values on Wednesday morning to northern and western parts of Minnesota. Some of the new records included; 35 F at Brimson; 38 F at Hibbing (tied 2007); 39 F at International Falls, Silver Bay, Crane Lake, Eveleth, and Orr; 45 F at Wheaton; and 46 F at Marshall and Worthington. The cold air finally cleared out on Thursday, and in contrast much of the balance of the month looks to be warmer than normal with above normal rainfall as well. That's Minnesota!

New Seasonal Climate Outlook

The NOAA Climate Prediction Center released new seasonal climate outlooks this week for the period August through October. The outlook favors cooler than normal temperatures for the western Great Lakes Region, including Minnesota. This is consistent with the pattern so far observed in July which shows most observers reporting mean monthly temperatures that range from 3 to 5 degrees F colder than normal.

The precipitation outlook is neutral, with equal chances for above or below normal values across the region during the August to October time frame. In any event, rainfall for the balance of the 2014 growing season is likely to be more variable across the Minnesota landscape.

Anniversary Week for Minnesota's Top Rain Storm

Today (July 18) is the anniversary of perhaps the most prolonged intense rainfall ever recorded in the state. This thunderstorm complex occurred in 1867 over western and central Minnesota, but was especially heavy in parts of Douglas, Pope and Stearns Counties, affecting the pioneer communities of Osakis, Westport, and Sauk Centre. Beginning late on Wednesday, July 17th, lasting all day July 18th, and into the early morning of Friday July 19th, heavy thunderstorms drenched the landscape with up to 30 inches of rainfall. Unfortunately measurements of the storm were not made by official rain gages in those days, but several people did record measurements via buckets and barrels which filled up. George B. Wright, a pioneer land surveyor in the area, documented the event and reported on it in some detail to the Minnesota Academy of Natural Sciences years later (1876). In his account, the Pomme de Terre, Chippewa, and Sauk Rivers, normally creeks at that time of year, became lakes several miles wide. The storm generated runoff caused the Mississippi to rise several feet (up to 12 ft in places), washing out bridges and logging booms right through the Twin Cities area. The total number of logs washed away was estimated to exceed 25 million. The mosquito population was reported as the worst ever for the balance of that 1867 summer. Even through the modern era this storm rainfall total has not even been approached. The greatest in the modern era was 17.21 inches near La Crescent, MN during the famous August 19, 2007 flash flood there.

Weekly Weather potpourri

NOAA released its State of the Climate in 2013 report this week. It highlights continued warm temperature trends and rises in sea level. It also highlights changes in Arctic sea ice, and regional climate trends. The report is 232 pages, but you can read the highlights.

With a return to warm, humid weather across the state next week, we may seen some Heat Advisories issued by the National Weather Service. In this context it might be wise to review some tips for maintaining good health during these hot spells. NOAA Public Affairs has issued four tips on preparing for heat spells. 

In addition, the EPA offers a guide book on coping with excessive heat and it too is available online as a PDF file. 

Late last month the city of Denver, CO released its first Climate Adaptation Plan. It is a comprehensive look at preparing for three features of the climate which are expected to change there: Increased temperature and urban heat island effects; Increased extreme weather events; Reduced snowpack and earlier snowmelt season. You can read more about this plan from the press release.

NOAA National Climatic Data Center recently released the statewide ranks for June temperature and precipitation in 2014. The Great Lakes Region had the wettest June in history, while the far west, notably CA and AZ had one of the warmest June months in history. You can view these rank maps at the NCDC web site.

Additional news from the western states is that Lake Mead is now at a historical low due to persistent drought in the west. Formed by the Hoover Dam, Lake Mead is the largest reservoir in the western states NV and AZ.

The Joint Typhoon Warning Center was issuing statements this week on Super Typhoon Rammasun which was headed for Vietnam and South China. Wind gusts were over 160 mph, creating sea wave heights of 35-40 feet. It will bring heavy rains to coastal areas throughout the coming weekend. Further north Tropical Storm Matmo was heading towards the coast of China between the Philippines and Japan. It was expected to strengthen over the weekend.

A NASA press release this week celebrates the 10th anniversary of the Aura Satellite system. Its package of instruments measures many of the greenhouse gases in the atmosphere and tracks their seasonal distribution. These data have been useful in tweaking climate models. Read more.

MPR listener question 

"It seems like our temperatures in Minnesota are always well above or well below normal. How do the standard deviations of temperature vary by season and are the standard deviations of daily temperatures larger here than in other states?"

Answer: Indeed the standard deviations in daily temperature do vary considerably by season. They are at their lowest values now (July). For example in July for the Twin Cities the standard deviations of daily maximum and minimum temperature are about plus or minus 6-7 degrees F. So the high temperature of 65 degrees F on Monday, July 14th in the Twin Cities was about 3 standard deviations from the mean maximum temperature value for the day (84 F). In contrast the standard deviations for daily maximum and minimum temperatures are plus or minus 13-15 degrees F during January when temperature variations are more amplified by cloud cover, air mass and presence or absence of snow cover.

Comparing to other geography, we can see that at Huntsville, Alabama this time of year the standard deviations of daily maximum and minimum temperature are just 3-4 degrees F, while in January they jump up to 10-11 degrees F, less than the variation we experience in Minnesota.

Twin Cities Almanac for July 18th

The average MSP high temperature for this date is 84 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 64 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for July 18th

MSP weather records for this date include: highest daily maximum temperature of 101 degrees F in 1940; lowest daily maximum temperature of 60 degrees F in 2000; lowest daily minimum temperature is 49 degrees F in 1873; highest daily minimum temperature of 80 F in 2011; record precipitation of 2.94 inches in 1895; and there has been no snow on this date.

Average dew point for July 18th is 62 degrees F, with a maximum of 81 degrees F in 2011 and a minimum of 44 degrees F in 2009.

All-time state records for July 18th

The state record high temperature for this date is 109 degrees F at Beardsley (Big Stone County) and Morris (Stevens County) in 1940. The state record low temperature for this date is 30 degrees F at Kelliher (Beltrami County) in 2003. State record precipitation for this date is 7.50 inches at Fort Ripley (Crow Wing County) in 1867; and no measurable snowfall has occurred on this date.

Past Weather Features

One of the coldest mid-July spells of weather occurred over July 18-19, 1912. Many observers reported overnight lows dropping into the 30s F, and some like Cloquet, Littlefork, and Roseau reported a mid-summer frost that damaged plants.

The hottest July 18th in history was in 1940 when over 25 communities reported daytime highs of 100 degrees F or greater. The coolest spot in the state that day was the Grand Marais Harbor with a high of just 59 degrees F. The July 1940 Heat Wave lasted until the 26th when a cold front brought rain and temperatures dropped into the 60s F.

Very strong thunderstorms moved across central and northern counties of Minnesota over July 17-18, 1952. Many observers reported 2-3 inches of rainfall, and a number of country roads and highways were flooded. Some record setting rainfalls included 6.10 inches at Gull Lake, 7.75 inches at Moose Lake, and 10.17 inches at Aitkin.

Between 6:00pm and 7:00pm on July 18, 1970 two tornadoes formed over central Minnesota. The first with winds over 158 mph tracked 4 miles across Douglas County near Lake Miltona, and it damaged several businesses, 28 homes, and 6 farms. The second tornado was on the ground in Anoka County for just 1 mile near Soderville. It damaged just a few homes.


Near normal temperatures on Saturday with a chance for showers and thunderstorms. Warmer on Sunday and Monday with a possibility of a heat advisory for some areas because of higher dewpoints. Chance for showers and thunderstorms on Tuesday and Wednesday of next week, with temperatures dropping back to near normal levels.

Friday, July 11, 2014

Cool July, sporadic rainfall: July 11, 2014 Commentary

In this edition of WeatherTalk

  • Cool July, sporadic rainfall
  • Weekly Weather potpourri
  • MPR listener question
  • Almanac for July 11th
  • Past weather 
  • Outlook

Cool July, sporadic rainfall

The month of July has started cool with most observers reporting average temperature for the month that ranges from 2-4 degrees F cooler than normal. Eight of the first ten days of the month were cooler than normal at Rochester, for example. Statewide this is the coldest first ten days of July since 2009. Some observers have reported daily record values of temperature.

Starting on July 1st a few locations reported new record cold high temperature values for the date including a high of just 57 degrees F at Crookston and Tamarac Wildlife Refuge, and a high of only 63 degrees F at Wheaton. On July 3rd Brimson (St Louis County) reported a new record minimum temperature of 36 degrees F, as did Long Prairie (Todd County) with a record minimum of 41 degrees F. On the holiday, July 4th observers at Crane Lake, Embarrass, Babbitt, and Brimson reported morning lows in the 30s F, though none of these were new record values. More recently this week on July 9th (Wed.) Hibbing reported a record low of 42 degrees F and Crane Lake a record low of 41 degrees F.

After a record-setting wet June, rainfall in July so far has been moderate to scarce in many areas, especially western counties. On the other hand northeastern and some central Minnesota counties have seen some heavy thunderstorms. These areas have reported over 2 inches of rainfall so far this month, while Grand Portage and Tofte have received over three inches, and Wadena has received over six inches. Heavy thunderstorms on Friday morning, July 11th brought some record-setting daily rainfall amounts. Based on preliminary reports these record amounts included 2.75" at Park Rapids, 4.83" at Wadena, 3.75" at New York Mills, 3.43" at Little Falls, and 2.33" at Onamia.

Weekly Weather potpourri

A tropical storm was passing near Guam in the Western Pacific Ocean this week. It was expected to strengthen before striking the Philippines early next week. Further to the north in the Western Pacific Ocean Basin Tropical Storm Neoguri brought heavy rains and high winds to parts of Japan this week, causing landslides and flash flooding in some areas.

Flash floods and large hail were reported in parts of Bulgaria, Poland, and Italy this week as a strong low pressure system made its way across eastern Europe. More showers with the possibility of hail were expected into the weekend.

A study released this week by the Children's Hospital of Philadelphia suggests a strong relationship between rising temperature and increased patient visits for kidney stones. Apparently as temperatures rise, especially in urban settings, there is a greater risk of dehydration and expression of kidney stone symptoms. Read more about this study.

MPR listener question 

I have hard Paul Huttner speak about the Twin Cities rainfall setting a pace to be the wettest year in history. What about other areas of the state and how about the frequency of rainfall, which seems unusually high as well?

Answer: Indeed, the Twin Cities reports 26.49 inches of precipitation so far this year, still on a record-setting pace. In addition precipitation has been recorded on about 10 more days than average for the Twin Cities (71 days so far compared to an average of 61). There are other communities that are also on pace to record their wettest year. Among these are:

  • Waseca with 26.21 inches so far and 74 days with measurable precipitation compared to an average of 59 days.
  • Redwood Falls with 22.25 inches so far and 67 days with measurable precipitation compared to an average of 43 days.
  • Itasca State Park with 20.19 inches so far and 75 days with measurable precipitation compared to an average of 52 days.
  • International Falls with 19.91 inches so far and 76 days with measurable precipitation compared to an average of 49 days.

Twin Cities Almanac for July 11th

The average MSP high temperature for this date is 84 degrees F (plus or minus 8 degrees F standard deviation), while the average low is 64 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for July 11th

MSP weather records for this date include: highest daily maximum temperature of 106 degrees F in 1936; lowest daily maximum temperature of 66 degrees F in 1941; lowest daily minimum temperature is 49 degrees F in 1945; highest daily minimum temperature of 82 F in 1936; record precipitation of 3.75 inches in 1909; and there has been no snow on this date.

Average dew point for July 11th is 60 degrees F, with a maximum of 80 degrees F in 1966 and a minimum of 35 degrees F in 2009.

All-time state records for July 11th

The state record high temperature for this date is 111 degrees F at Ada (Norman County) in 1936. The state record low temperature for this date is 30 degrees F at Meadowlands (St Louis County) in 1985. State record precipitation for this date is 7.47 inches at Rochester (Olmsted County) in 1981; and no measurable snowfall has occurred on this date.

Past Weather Features

July 11, 1936 was not only the hottest in Minnesota history but marked the mid-point of a two-week long Heat Wave which brought day after day of 100 degrees F or greater to many communities. It was by far the most intense and longest Heat Wave in state history, contributing to the death of over 900 citizens. Over 75 communities reported temperatures of 100 degrees F or higher.

Powerful thunderstorms crossed the state over July 11, 1981 bringing strong winds and heavy rains. Rainfall was especially heavy and intense in Olmsted, Fillmore, and Wabasha Counties where many roads and highways were flooded. The Rochester Airport was also closed for a period of town and many residents of Preston were evacuated from their homes because the Root River as flooding over its banks. Rainfall amounts included 3.27" at Grand Meadow, 4.10" at Zumbrota, 5.85" at Lanesboro, 7.30" at Preston, and 7.47" at Rochester.

July 11-12, 1985 brought a cold snap to northern Minnesota communities. Seven communities reported morning lows in the 30s F, with some ground frost at Cotton, Tower, Virginia, and Babbitt. It was short-lived as temperatures warmed into the 80s F by the afternoon of the 12th.

On July 11, 2005 three tornadoes were spotted in northwestern Minnesota, two in Roseau County and one in Marshall County. Fortunately they occurred in rural areas and did little damage.


Near normal temperatures to start the weekend, but with higher humidity and chances for scattered showers and thunderstorms Saturday and Saturday night. Somewhat cooler and drier on Sunday, then significantly cooler on Monday with a chance for scattered showers and thunderstorms. Continued cool weather for Tuesday and Wednesday and mostly dry weather. Chance for showers and thunderstorms each day, with temperatures significantly cooling off on Sunday and Monday. Cooler than normal next week and generally dry weather. Warming to near normal temperatures by next weekend.

-Mark Seeley

Thursday, July 3, 2014

June Record Rainfalls: July 4, 2014 Commentary

In this edition of WeatherTalk

  • Early Edition
  • June Record Rainfalls
  • Weekly Weather potpourri
  • MPR listener question
  • Almanac for July 4th
  • Past weather 
  • Outlook

Early Edition

With the July 4th holiday on Friday this year, there will not be an MPR segment associated with the Minnesota WeatherTalk weekly newsletter, so I am sending this abbreviated version out early, to enjoy the 3-day weekend.

June Record Rainfalls

Though June temperatures around the state were near normal, rainfall was far from it, in fact record-setting for many communities. On a statewide basis the average rainfall for June was 8.09 inches, a record historical high not only for June, but for any month of the year. The previous wettest months in Minnesota history on a statewide basis were June of 1914 and July of 1897 with values of 7.32 inches.

Those individual climate stations setting records for the wettest June include:

  • Ada 9.20 inches
  • International Falls 10.24 inches
  • Littlefork 9.23 inches
  • Waskish 8.93 inches
  • Kabetogama 11.58 inches
  • Benson 10.49 inches
  • Dawson 8.27 inches
  • Chaska 13.84 inches
  • Glencoe 14.61 inches
  • Lakefield 10.96 inches
  • Luverne 13.84 inches
  • Redwood Falls 14.24 inches
  • Amboy 10.29 inches
  • Faribault 12.96 inches
  • Waseca 12.93 inches
  • Hastings Dam 10.69 inches

Many observers reported measurable rainfall on over half of the days during the month of June, and over 90 climate stations recorded 10 or more inches for the month. Several reported record-setting daily values. In fact well over 100 daily record rainfall values were measured during June, including: Luverne with 3.39 inches on the 1st and 3.57 inches on the 15th; Redwood Falls with 3.41 inches on the 1st and 5.10 inches on the 19th; Waskish with 3.46 inches on the 12th; Worthington with 3.73 inches on the 15th; Gaylord with 4.87 inches on the 19th and 2.92 inches on the 20th; Lake Wilson with 5.20 inches on the 15th; Redwing with 4.41 inches on the 15th; and MSP with 4.13 inches on the 19th (largest June daily rainfall in history).

The acknowledged statewide June rainfall record from the Cooperative Observer network in Minnesota is 15.63 inches at Delano in 2002. This record was not broken. MSP Airport with a June rainfall total of 11.26 inches marked the 2nd wettest June month in history, trailing only 11.67 inches in 1874.

At one point during June over 80 percent of all the stream gages in Minnesota watersheds were reported volume flows in above the historical 90th percentile or above flood stage, a remarkably high fraction for the state in historical terms.

Final June climate summaries are available on the climate website.

Weekly Weather potpourri

Iowa reported a remarkable wet June as well, with many new station records set. At least 90 weather observers reported total monthly rainfall of 10 inches or greater. Among the new records were 15.90 inches at Greenfield, 16.65 inches at Sioux City, 16.33 inches at Sioux Rapids, and 16.92 inches at Cherokee.

Similarly, South Dakota reported a very wet June, with over 30 climate stations receiving 10 or more inches of rainfall. Dennis Todey, South Dakota State Climatologist reported that the Canton, SD just south of Sioux Falls received 18.75 inches of rainfall, a new statewide record for the month, breaking the old record by more than 2.5 inches.

A hot and stormy month of June for parts of France, ended with a hail storm over the Burgundy areas this past weekend. Golf ball size hail caused widespread damage to vineyards there with reported losses of 50 to 90 percent of the grapes in some areas. Reports indicate it will not be a good harvest for wind grates this year in the Burgundy area.

During the four-week period ending on July 1, 2014, contiguous U.S. drought coverage declined 3.31 percentage points to 34.01%. Coverage reached its year-to-date peak of 40.06% on May 6, but subsequent rainfall across portions of the nation’s mid-section has reduced drought’s imprint.

A nationwide drought update from Brad Rippey of the USDA this week included these comments:
Drought still covers a substantial portion of the central and southern Plains and the western U.S. On July 1, the highest level of drought­ D4, or exceptional drought­ was noted in portions of California (36%), Nevada (11%), Oklahoma (7%), Texas (5%), and Colorado (2%). California also led the nation with 79% coverage of extreme to exceptional drought (D3 to D4). According to the latest “agriculture in drought” statistics, based on the July 1 Drought Monitor, 25% of the domestic hay acreage and 36% of the U.S. cattle inventory were located in a drought-affected area. Near-record to record-setting June rainfall eradicated residual drought from the Midwest. As a result, drought covered just 5% of the U.S. soybean area and 8% of the corn area by July 1. Consequently, roughly three-quarters of the U.S. corn and soybeans were rated in good to excellent condition by the end of June. Corn, rated 75% good to excellent on June 29, has not been rated as highly at this time of year since 2003. That year, on the same date, corn was also rated 75% good to excellent. Soybeans, rated 72% good to excellent on June 29, have not been rated as highly at this time of year in the last two decades.

The National Hurricane Center was issuing advisories for Hurricane Arthur this week off the southeast coast. It was bringing some rain and wind to the coastal areas of SC and NC and was expected to persist into the weekend, before dissipating on Monday (July 7th).

MPR listener question

"How often has the daytime temperature remained below 80 degrees F on July 4th in the Twin Cities, as it is expected to do this year?"

Answer: Actually this probably happens more frequently than you think, about 30 percent of the time since 1873. The last 4th of July in the Twin Cities when the temperature did not reach 80 degrees F was in 2009, when the high was 78 degrees F.

Twin Cities Almanac for July 4th

The average MSP high temperature for this date is 82 degrees F (plus or minus 7 degrees F standard deviation), while the average low is 62 degrees F (plus or minus 6 degrees F standard deviation).

MSP Local Records for July 4th

MSP weather records for this date include: highest daily maximum temperature of 100 degrees F in 1949; lowest daily maximum temperature of 58 degrees F in 1967; lowest daily minimum temperature is 43 degrees F in 1972; highest daily minimum temperature of 80 F in 1999; record precipitation of 2.27 inches in 1900; and there has been no snow on this date.

Average dew point for July 4th is 59 degrees F, with a maximum of 79 degrees F in 1999 and a minimum of 40 degrees F in 1972.

All-time state records for July 4th

The state record high temperature for this date is 107 degrees F at Pipestone (Pipestone County) and Worthington (Nobles County) in 1936. The state record low temperature for this date is 27 degrees F at Tower (St Louis County) in 1972. State record precipitation for this date is 9.78 inches at Milan (Chippewa County) in 1995; and no measurable snowfall has occurred on this date.

Past Weather Features

The warmest ever July 4th on a statewide basis was in 1949 when 18 communities reported an afternoon high temperature of 100 degrees F or greater. The heat was compounded by very high dewpoints that day (low to mid 70s F), sending the Heat Index soaring to the range of 110 to 115 degrees F. The lemonade and beer vendors were very busy.

The coldest 4th of July probably occurred in 1972 when many central and northern Minnesota climate stations reported low temperatures in the 30s F. Even daytime high temperatures remained in the 60s F as far south as Winnebago and Zumbrota.

Heavy thunderstorms moved across the state on July 4, 1995. Observers in Benson and New London reported over 4 inches of rain, with flash flooding, while the observer at Milan reported the heaviest rain in history with 9.78 inches.

The famous "derecho" storm (straight line winds) devastated the BWCA of northeastern Minnesota on July 4, 1999. Winds from 80 to 100 mph cut a damage swath of 600 square miles through Superior National Forest.


Warming temperature over the weekend with a chance for widespread showers and thunderstorms. Quite warm on Sunday. Cooler next week with a chance for showers on Tuesday and Wednesday.

-Mark Seeley
  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy