Week of heat and severe weather caps off active month of July
Oct 23, 2023
Meteorologist & Multimedia Journalist
ROCKFORD — The month of July came to a calm and relatively cool end on Monday, capping off a month of big temperature swings and bouts of severe weather.
As much of Illinois has been in drought since spring, the area was in desperate need for beneficial rainfall, as crops began showing signs of stress and farmers becoming concerned about the health of their product.
July is typically the warmest month of the year and this month did not disappoint on that front, but the statistics of the month's temperatures may surprise you.
Here is a breakdown of how the month of July ended up weather-wise, along with a recap of a month filled with activity.
Note: Averages are measured from the 30-year period between 1991 and 2020. Weather records for the City of Rockford go back to 1905.
Despite how the month ended, temperatures averaged out slightly below normal, the first such month since March.
Overnight lows actually weigh the average down, with nighttime temperatures ending up just over 2° below average at 61.5°.
Afternoon highs, however, averaged out perfectly at the 30-year normal, which is 83.9°. The highest temperature recorded at the Chicago-Rockford International Airport was 92° on July 28, although the heat index at the time was 108° thanks to very humid air.
It took all of that heat we felt in the last week of the month to warm back up closer to average, but most of the month saw pleasant conditions.
As we entered the month of July, we were in desperate need of rainfall, needed a wetter July to keep crops and other plants stable after what has been a dry end to spring and start to summer.
Through the middle of the month, it appeared the status quo would remain. Despite occasional thunderstorms, conditions remained below average, even getting as low as an inch behind schedule, compounding the extremely dry months that preceded.
It was the multiple rounds of severe weather that busted the Stateline out of its dry stretch. Rockford ended up with 4.32" of rain when all was said and done, just over a half-inch above average.
The biggest daily rainfall total of the month was 1.30" on July 28, mainly due to severe thunderstorms which caused flooding to parts of the Rockford metro.
Going into the month, the vast majority of northern Illinois was under severe drought, but these repeated bouts of rainfall have improved conditions for the most part, but much of the area remains in drought.
It was those several bouts with severe weather, almost exclusively in the latter half of the month, which brought us a wetter-than-average month. It also caused damage to parts of the Stateline in several forms.
On July 12, an EF-0 tornado cut a path through a neighborhood in western Boone County near the Winnebago County line. It touched down just northeast of Mercyhealth Sportscore Two, snapping and uprooting trees and causing some damage to homes along a 2.5 mile path in just four minutes before lifting near Beloit Rd.
That tornado was just one of 13 tornadoes in northern Illinois that day, with the other dozen tornadoes touching down in the Chicago suburbs. All of the tornadoes were rated either an EF-0 or EF-1 on the scale from zero to five.
For the second day, severe storms moved through the Stateline, triggering tornado warnings.
The next day, a storm moving southeast across southern Wisconsin and northern Illinois spawned numerous funnel clouds, causing the National Weather Service to issue Tornado Warnings for parts of Boone and McHenry Counties. The NWS office in Milwaukee did confirm a tornado that briefly touched down just east of Janesville in Rock County, causing tree damage in a farm field.
For a third day in a row, on July 14, severe storms once again swept through the Stateline. Damage was more widespread this time, particularly in Ogle and Lee Counties. Winds of over 60 mph caused tree and power line damage in Dixon, Oregon, Amboy, and Lindenwood, while a funnel cloud was reported along the Lee/Ogle County Line near Lost Nation.
As we calmed down into the next week, our air also become polluted, once again, with smoke from Canadian wildfires. This was a somewhat common occurrence throughout the month, with the Chicago-Rockford International Airport recording seven days of mentionable haze.
READ MORE: Where do the air quality index numbers come from?
Air quality levels were not as hazardous as they were with a particularly heavy plume of smoke that came overhead in June, but the story of Canadian wildfire smoke creating hazy skies for much of the Midwest most definitely continued throughout July.
A heat wave ramped up across much of the Midwest, including the Stateline, later that week. Temperatures were sent soaring into the 90s for multiple days, with high humidity bringing heat indices well into the 100s.
Our area sat right on the edge of this "Ring of Fire" pattern, meaning we were on a favorable track for multiple rounds of severe thunderstorms.
We first felt the brunt of the severe weather on the morning of July 26, when a round of particularly strong thunderstorms rolled through areas near the IL/WI state line. Winds of up to 70 mph were reported, causing extensive damage in Loves Park and Machesney Park, along with damage to trees and power lines for many areas mainly north of U.S. 20.
As the sweltering heat continued, July 28 saw two rounds of severe storms move through the area. The first brought wind gusts over 70 mph in the Polo area, causing trees and power lines to go down across much of Lee and Ogle Counties, causing power outages on the hottest day of the year.
In the evening, a more widespread round of severe thunderstorms came through, dumping tremendous amounts of rain in parts of the area and causing additional wind damage in areas already cleaning up debris from previous storms.
Strong storms impacted the Stateline on Friday evening. Here are photos and videos from our 13 WREX community.
The most rain was observed just outside of Belvidere, where observers recorded nearly 3.25" of rain. Highest amounts of rain fell along the U.S. 20 corridor, causing some flooding in the Rockford metro area.
More damage caused by winds of up to 80 mph was reported in parts of the Stateline, including damage to homes and trees near Candlewick Lake in Boone County, Polo, Dixon, and in rural Stephenson County. A brief EF-0 tornado crossed the Mississippi River from eastern Iowa into the Fulton area in northeastern Whiteside County.
Looking ahead to the month of August, things look to cool down a bit as we begin the slow transition away from summer and into fall.
Early in the month, extended forecasts from the Climate Prediction Center indicate cooler-than-average temperatures are favored for much of the central U.S., while most of the country leans towards a wetter start to the month.
For the entire month, however, CPC outlooks indicate conditions will even out, with the "Ring of Fire" pattern staying just to our south, keeping the favorable storm track and summer heat away from the Stateline.
That doesn't mean that we totally escape any storms for the month, however, so make sure to keep in touch with Your 13 Weather Authority forecasts to stay one step ahead of whatever else Mother Nature has in store for the rest of the summer.
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Meteorologist & Multimedia JournalistSlightly CoolerDrought Dented, But Not EliminatedActive MonthREAD MORE: Where do the air quality index numbers come from?What about August?