Overview & Graphics

In spite of a brief heat wave, this past August as a whole ended with near-normal temperatures across the area. It was also relatively dry across most of the area with the monthly precipitation totals for both Chicago and Rockford ending up nearly 3” below normal.

CoCoRaHS Observer Monthly Precipitation Summary

This year’s meteorological summer concluded with near-normal temperatures for the season. Most of the area finished with near to below normal precipitation, though a couple of localized heavy rain events led to a few exceptions.

CoCoRaHS Observer Seasonal Precipitation Summary

Public Information Statement
National Weather Service Chicago IL
201 PM CDT Fri Sep 1 2023 /301 PM EDT Fri Sep 1 2023/

...A Look Back at the Climate for Meteorological Summer (June,
July, August) 2023 for Chicago and Rockford...

At Chicago, the average high temperature was 83.0 degrees, which
is 0.5 degrees above normal. The average low temperature was
64.1 degrees, which is equal to normal. The average temperature
for the season was 73.6 degrees, which is 0.3 degrees above
normal. 11.30 inches of precipitation were recorded, which is
0.76 inches below normal.


Records established or tied during the summer months:

June: None

July:
* Record daily precipitation of 3.35 inches on July 2nd.
** 7th wettest July on record since 1871 with 7.61 inches of
   precipitation.

August:
* Record daily maximum temperature of 98 degrees on the 23rd.
* Record daily highest minimum temperature of 77 degrees on the
  23rd.
* Record daily maximum temperature of 100 degrees on the 24th.

No top ten seasonal records were set this past summer.

-----------------------------------------------------------------

At Rockford, the average high temperature was 82.5 degrees, which
is 0.3 degrees above normal. The average low temperature was 60.0
degrees, which is 1.7 degrees below normal. The average temperature
for the season was 71.3 degrees, which is 0.6 degrees below normal.
7.63 inches of precipitation were recorded, which is 5.60 inches
below normal.


Records established or tied during the summer months:

June:
* Record daily minimum temperature of 41 degrees on the 12th.

July: None

August:
* Record daily highest minimum temperature of 78 degrees on the
  24th.

No top ten seasonal records were set this past summer.

$$

Latest Seasonal Climate Report:   Chicago    |    Rockford

Public Information Statement
National Weather Service Chicago IL
1154 AM CDT Fri Sep 1 2023 /1254 PM EDT Fri Sep 1 2023/

...A Look Back at the Climate for the Month of August 2023 for
Chicago and Rockford...

At Chicago, the average high temperature was 83.0 degrees, which
is 0.5 degrees above normal. The average low temperature was
65.5 degrees, which is 0.4 degrees above normal. The average
temperature for the month was 74.3 degrees, which is 0.5 degrees
above normal. 1.33 inches of precipitation were recorded, which
is 2.92 inches below normal.

The following daily records were set for Chicago during the month
of August 2023:
* Record daily maximum temperature of 98 degrees on the 23rd.
* Record daily highest minimum temperature of 77 degrees on the
  23rd.
* Record daily maximum temperature of 100 degrees on the 24th.

No top ten monthly records were established for Chicago in August
2023.


At Rockford, the average high temperature was 81.1 degrees, which
is 0.9 degrees below normal. The average low temperature was
62.0 degrees, which is 0.2 degrees above normal. The average
temperature for the month was 71.6 degrees, which is 0.3 degrees
below normal. 1.41 inches of precipitation were recorded, which
is 2.78 inches below normal.

The following daily records were set for Rockford during the
month of August 2023:
* Record daily highest minimum temperature of 78 degrees on the
  24th.

No top ten monthly records were established for Chicago in August
2023.

$$

Latest Monthly Climate Report:   Chicago    |    Rockford

Events

• July 2, 2023: Significant flash flooding in Chicago and nearby suburbs
• July 12, 2023: Localized tornado outbreak with 13 tornadoes across northeast Illinois
• July 14, 2023: Storms produce damaging winds across northern Illinois and an EF-0 tornado in DuPage County
• July 28-29, 2023: Multiple rounds of storms, including several late night tornadoes and damaging winds
• August 23-24, 2023: Late summer heat wave results in consecutive days with 115+° heat indices

NWS Chicago Science and Past Events Page