The preliminary statewide average July temperature was 78.3 degrees, 2.9 degrees above the 1991–2020 average and tied for 16th warmest on record going back to 1895. The preliminary statewide total July precipitation was 5.95 inches, 1.89 inches above the 1991–2020 average and the 10th wettest on record.
Data are provisional and may change slightly over time.
Persistently High July Temperatures
July is the climatologically hottest month of the year in Illinois, and last month played its role. Daily temperatures from Carbondale in Figure 1 show temperatures were above normal in all but three days of the month. No July day was more than 8 degrees warmer than normal, so we didn’t necessarily have many extreme heat days. Instead, July was more of a simmer, with persistently high temperatures and humidity
July average temperatures ranged from the mid-70s in far northern Illinois to the low 80s in south-central Illinois, between 1 and 6 degrees above normal for most of the state (Figure 2). Persistent southwest flow maintained consistently high temperatures and humidity. Some of the more impressive daily high temperatures last month included 98 degrees in Rock Island and 97 in Charleston. The high humidity kept nighttime low temperatures especially high, including 80-degree low temperatures at Rend Lake and Chicago Midway. In fact, the July average daily low temperature was the highest on record in Danville (69.7 degrees) and the second highest on record in Peoria (70.8 degrees).
Overall, the preliminary statewide average July temperature was 78.3 degrees, 2.9 degrees above the 1991–2020 average and tied for 16th warmest on record going back to 1895.
Oh, the Humidity!
Illinois summers tend to be very humid, perhaps a less than profound truth. However, persistent atmospheric flow out of the south and southwest, along with abundant soil moisture in most parts of Illinois, made last month extremely humid. The dew point temperature is a good way of representing how we experience humidity. Illinoisans generally start to feel the weather as humid when the dew point gets above 60 degrees; we begin to feel uncomfortable with dew points above 65 degrees, and anything at or above 70 degrees is very uncomfortable. Table 1 shows how often we experienced dew point temperatures at or above 70 degrees last month in multiple locations. Most of central and southern Illinois had more than 450 hours last month (> 60% of all hours) with a dew point at or above 70 degrees, the most on record in Peoria, Springfield, and Paducah. In fact, Paducah experienced a dew point temperature at or above 70 degrees 87% of the time last month, breaking the previous record there of 633 hours in the infamous year of 1993.
Wet July Keeps Crops (and Fungi) Happy
The start of the growing season was dry in northern and parts of central Illinois. While the first half of July largely maintained that dry pattern, the second half of the month let loose and washed away drought concerns in much of Illinois. July total precipitation ranged from around 2.5 inches in southwest Illinois to nearly 15 inches in parts of western and south-central Illinois. Most of the state was 1 to 5 inches wetter than normal last month, while parts of east-central and southern Illinois were a bit closer to normal if not slightly drier than normal in July (Figure 3).
Some of the more impressive July rainfall totals include 13.4 inches in Jerseyville and 11.7 inches in Dixon. In contrast, stations in Perry County and eastern Champaign County had just over 2 inches of total rainfall last month, between 2 and 3 inches below normal.
Very Heavy Rain, but Very Few Tornadoes
It seems that every July brings one or more extreme rainfall event that causes significant flooding damage. Unfortunately, last month followed this pattern. The Chicago National Weather Service Office was particularly busy last month, with two very intense rainfall events and associated urban flooding in July. The first of these included a measure of 5.12 inches of rain in just 90 minutes near the United Center in Chicago. Not to be outdone, a second storm produced over 6 inches of rain in around 90 minutes near Midway Airport (Figure 4). A different storm moved over south-central Illinois overnight on July 20th-21st, and produced exceptionally heavy rain around the Vandalia and Brownstown areas in Fayette County, including a report of 13.5 in less than 12 hours. All of these events caused significant flooding, including many flooded basements in Cook County, and inundated fields and crop damage in parts of Fayette County.
Despite the heavy rainfall and storms, we did not have a very active severe weather month in July. The NOAA Storm Prediction Center only reported 1 tornado in Illinois last month, an EF-0 in Fayette County. We did have 113 severe wind reports and 10 severe hail reports last month, most of which were in the northern two-thirds of the state.
As of August 1, Illinois had an unofficial total of 131 tornadoes in 2025 according to the Storm Prediction Center. This is a preliminary total and may be adjusted later this year as reports are refined. However, if that total is accurate, it would give this year the second highest tornado frequency on record for any year, with only last year (2024) surpassing this total.
Outlooks
August is the beginning of the end of summer but can certainly bring its fair share of heat. August is also an important month for finishing crops as we move toward fall. Climate Prediction Center outlooks for August don’t have much information for us, with equal chances of above and below normal temperatures and precipitation statewide. (Figure 7)
The newest climatological fall (September – November) outlooks show strong chances a warmer than normal fall, with higher chances of drier conditions to our north and west (Figure 7).
