August 2021 and Meteorological Summer Climate Summary

Overview & Graphics

Chicago and Rockford Monthly Summary

Public Information Statement
National Weather Service Chicago IL
959 AM CDT Wed Sep 1 2021 /1059 AM EDT Wed Sep 1 2021/

...A Look Back at the Climate for the Month of August 2021 for
Chicago and Rockford...

At Chicago, the average high temperature was 86.2 degrees, which
is 3.7 degrees above normal. The average low temperature was 68.1
degrees, which is 3.0 degrees above normal. The average
temperature for the month was 77.1 degrees, which is 3.3 degrees
above normal. During the month of August, 4.51 inches of
precipitation were recorded, which is 0.26 inches above normal.

There were no daily records set during the month of August 2021
for Chicago.

One Top Ten Monthly Record was set:
**6th warmest August on record since 1872.

At Rockford, the average high temperature was 86.5 degrees, which
is 4.5 degrees above normal. The average low temperature was 63.6
degrees, which is 1.8 degrees above normal. The average
temperature for the month was 75.1 degrees, which is 3.2 degrees
above normal. During the month of August, 3.61 inches of
precipitation were recorded, which is 0.58 inches below normal.

One daily record was set for Rockford during the month of August
2021:
* Record daily precipitation of 2.52 inches on the 9th.

$$

BKL

Latest Monthly Climate Report:   Chicago   |   Rockford  

Chicago and Rockford Seasonal Summary

Public Information Statement
National Weather Service Chicago IL
1152 AM CDT Wed Sep 1 2021 /1252 PM EDT Wed Sep 1 2021/

...A Look Back at the Climate for Meteorological Summer (June, July,
August) 2021 for Chicago and Rockford...

At Chicago, the average high temperature for the summer season was
84.1 degrees, which is 1.6 degrees above normal. The average low
temperature was 66.5 degrees, which is 2.4 degrees above normal.
The mean temperature for the season was 75.3 degrees, which is 2.0
degrees above normal. A total of 13.19 inches of precipitation
was recorded during this past summer, which is 1.13 inches above
normal.

Records established or tied during the summer months:

June:
* Record daily precipitation of 1.50 inches on the 12th.
** June 2021 tied as 4th hottest June in Chicago, previously set in
1952.

July: No daily or monthly records.

August: No daily records. August 2021 was the 6th hottest August for
Chicago.

The 2021 Meteorological Summer for Chicago tied for the 8th
hottest summer previously set in 1953 and 1973.

At Rockford, the average high temperature was 86.0 degrees, which
is 3.8 degrees above normal. The average low temperature was 64.3
degrees, which is 2.6 degrees above normal. The mean temperature
for the season was 75.1 degrees, which is 3.2 degrees above
normal. A total of 7.14 inches of precipitation was recorded
during this past summer, which was 6.09 inches below normal.

Records established or tied during the summer months:

June:
* Tied record daily maximum temperature of 94 degrees on the 5th.
* Record daily maximum temperature of 94 degrees on the 9th.
* Record daily maximum temperature of 99 on the 11th.
* Record daily maximum temperature of 95 on the 12th.
** June 2021 was the 4th hottest June for Rockford. This June was
also the 6th driest June for Rockford.

July: No daily or monthly records.

August:
* Record daily precipitation of 2.52 inches on the 9th.

The 2021 Meteorological Summer for Rockford was the 5th hottest
summer.

$$

BKL

Latest Seasonal Climate Report:   Chicago   |   Rockford  

Events

• August 24, 2021: Thunderstorms produce wind damage and localized flooding in northern Illinois

• August 12, 2021: Significant flash flooding in and near Gibson City, IL

• August 10-11, 2021: Multiple rounds of severe storms produce widespread wind damage

• August 9, 2021: Numerous tornadoes and significant rainfall for parts of northern IL

• July 29, 2021: Overnight severe thunderstorms produce wind damage across the Chicago metro

• July 24, 2021: Gusty thunderstorms track across part of the area

• July 12, 2021: Significant flash flooding in and near Seneca, IL

• June 25-26, 2021: Severe storms produce four tornadoes and flash flooding

• June 20-21, 2021: Late night tornadoes & wind damage, including an EF-3 tornado in Naperville and Woodridge

• June 11-12, 2021: Localized severe thunderstorms produce hail and damaging winds

NWS Chicago Science and Past Events Page