July 2019 Weather Summary: Warm with Variable Rainfall

August 5, 2019 // Article by: Jim Sullivan

This July was what can be called a typical warm summer month in the Midwest, with plenty of heat and not as much rain as some previous spots for most areas. All locations were a few degrees warmer than average, with Dayton leading the way at 3.8 degrees above-average.  Chicago also came in at more than 3 degrees over the norm, 3.1 degrees to be exact.  Columbus and Indianapolis both were 2.8 degrees warmer than average for the month, with Cincinnati rounding out the list at +2.4 degrees.  Rain varied, though many areas were drier than recent months.  Dayton was the wet spot, seeing 5.71" of rain, which is 1.60" above average.  Nearby Columbus and Cincinnati were much drier, with 3.22" and 2.41" of rain respectively, both more than an inch below normal.  Indianapolis came in with 3.86" (-0.69"), while Chicago came in at 3.94" (+0.24"). 

As can be expected in a hotter than normal July, the region had plenty of stretches of 90-degree weather. Everyone saw multiple high temperatures in excess of 90 early in the month between the 1st and 5th, with many areas seeing another day or two above 90 around the 10th. The hottest stretch was the third week of the month, when everyone saw several days in which the high temperature topped 90, which combined with tropical humidity levels and very warm overnight lows to result in a sultry week. All cities got into double digits for the number of 90-degree days in July, and all saw more such days than normal.

While no daily record highs were broken, some of the overnight lows were warm enough to break records on July 19th; Indianapolis only dipped to 79 degrees, tying the record for the day. Chicago failed to even bottom out at 80 degrees, with a low of 81, breaking the old record for the date of 78 degrees. This is the warmest low temperature in Chicago since July 23, 2012 when the low was also 81°F.


A disturbance combined with the heat and humidity to spark areas of thunderstorms on July 2nd

With all the heat and humidity came scattered thunderstorms at various points. Many thunderstorms produced heavy rain and localized flooding, though the hit-and-miss nature of the storms prevented more widespread flooding problems. As can be seen by most locations being near-normal for rainfall on the month, these thunderstorms weren’t much more frequent than normal, outside of perhaps the first week of July in Ohio. Some isolated severe weather occurred through the month, though there weren’t any significant outbreaks. The most widespread severe weather occurred on July 2nd, when fairly numerous thunderstorms produced damaging winds across parts of Illinois, Indiana, and Ohio. Thunderstorms were also fairly numerous on July 20th and 21st across the region as a cold front moved through and broke the heat, with some thunderstorms again producing damaging winds.

Tree damage outside of Chicago on July 20th from severe thunderstorms