In general, the Summer of 2014 was mild with the record setting June rainfall more than made up for a late summer dry spell. June set the stage for the summer with ample rainfall statewide with many places from St. Cloud to the Iowa border seeing eight inches of rain for the month or more. This is twice the 1981-2010 June normal. A few places saw over a foot of rain for the month with Redwood Falls and Glencoe both seeing 14.24 inches.
A dry spell began during the third week of June and ended about the third week of August. It wasn't enough to erase the June surplus, but was enough to produce some abnormally dry conditions over south central and southeast Minnesota. Any developing drought was held in check by rather mild temperatures. There was a lack of hot days this summer in Minnesota. Duluth and Rochester did not reach 90 degrees. The warmest temperature of the year was 96 degrees at Hutchinson on July 22 and this is the coolest statewide high temperature for the summer in 21 years when it was also 96 degrees in 1993.
One explanation for the mild summer is that there was a lack of a persistent high pressure ridge over the upper midwest during the summer and the jet stream tapped some cooler Canadian air at times as well. While there were some bouts of severe storms, the tornado count this summer was fairly low not only in Minnesota but across the country as well. In Minnesota, preliminary numbers indicate about two dozen tornadoes or less, compared to the 20 year median of 35.
Below is a summer table from June 1 to August 31 for larger cities in the region depicting the maximum and minimum temperature of the summer along with total precipitation. Interestingly the average temperature for some locations wound up being above normal for the summer.
Hi Lo Ave Dep from Total Dep from Temp Normal Precip Normal -------------------------------------------------- Fargo 93 44 68.7 -0.2 9.44 0.19 Grand Forks 92 44 67.0 0.4 13.50 3.99 Duluth 88 42 63.8 0.4 12.52 0.74 Int Falls 90 34 62.0 -1.1 15.72 5.29 St. Cloud 94 46 70.0 2.0 13.02 1.75 Twin Cities 92 49 71.5 0.2 16.53 3.94 Sioux Falls 92 44 69.6 -0.9 19.45 9.39 La Crosse 91 50 72.2 0.7 16.32 3.43 Rochester 87 47 68.9 -0.4 14.09 0.34 Temperatures in degrees F, Precipitation in inches.