June 2015 in the Midwest was a very wet and active month. In fact, many locations across the area reported a top 10 wettest June on record! Rain that fell during June caused flash flooding issues in some areas and there were several rounds of severe weather as well.
The month began with chilly weather as high pressure nosed in from the northeast, with temperatures 5-15 degrees below average. In fact, Columbus, Dayton, and Cincinnati all failed to reach 60 degrees for a daily high temperature on the 1st. Warmer weather returned quickly, however, and continued through the remainder of the month. While rather dry weather was seen across the area through the 7th, the 8th featured more rainfall with the Indianapolis area recording 1.90” of rainfall.
Hot and humid weather then pushed in after the 9th, and was responsible for active weather in the Chicago area through the 11th. In fact, 1 – 2” diameter hail was reported on the 10th with amazing softball sized hail observed just southwest of Joilet, IL! Meanwhile, a heat wave broke out across Ohio with readings reaching or topping 90 degrees for 5 days straight from the 10th to the 14th. A cold front then crossed the area on the 15th and 16th, with a round of thunderstorms and even an EF-1 tornado reported in Will County, IL on the 15th. In addition, Chicago O’Hare reported 2.56” of rainfall on the 16th, accounting for a third of the month’s total precipitation!
Radar image from June 20th as the remnants of Bill moved through the Ohio Valley. Courtesy of the College of DuPage.
High pressure over the Southeast U.S. then forced the same front slowly back north, with volatile weather returning to the Midwest. From the 17th - 19th, Indianapolis, IN through Dayton, OH was soaked in over 2.00” of rain, with numerous reports of wind damage on the 18th as severe t-storms brought 60 mph wind gusts. Without much break, the remnants of Tropical Storm Bill swung through on the 20th, and brought additional heavy rainfall and storms. The Columbus area saw the worst of it, as the airport recorded 2.00” of rain on the nose. Lesser amounts were seen in Indy and Chicago. A few days later, on the 22nd, severe weather generally missed the Chicago Metro area, but just to the southwest, a persistent supercell dropped 10 tornadoes from Whiteside through Kankakee counties in Illinois! The strongest of which was an EF-3 tornado with maximum winds of 160 mph in Coal City, IL.
Storm reports from NOAA/NWS/SPC for June 22, 2015.
Though the persistent high pressure in the southeast broke down over the last 9 days of the month, a trough began building into the eastern half of the U.S., bringing with it more unsettled weather. Temperatures also began to cool down some, generally 4 - 10 degrees below average to end the month. As for rainfall, the last large area of low pressure swept through the region mainly on the 27th – 28th, and brought heavy, flooding rains from Indy on east. For the month as a whole, northern Illinois through Ohio finished 3.50 – 4.00”+ above normal in the rainfall department, while temperatures ended up mainly within a degree of normal.
