August weather in Summit, IL
The average temperature in Summit in August is 74.5°F (66.4°F–82.7°F). Average precipitation: 3.99 inches.
August is a summer month in Summit, and is warmer than the annual average of 52.1°F. Daily temperatures swing about 16.3°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 13h 41m. For travel, August is a comfortable month to visit.
Avg High
82.7°F
Avg Low
66.4°F
Precipitation
3.99 in
Daylight
13h 41m
August records in Summit
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 98.1°F (2006) | 60.1°F (2019) | 0.93 in (2024) |
| August 2 | 97.0°F (2006) | 57.9°F (2009) | 3.14 in (2001) |
| August 3 | 95.0°F (2022) | 57.9°F (2000) | 1.60 in (2010) |
| August 4 | 96.1°F (2018) | 55.9°F (2017) | 1.89 in (1998) |
| August 5 | 95.0°F (2018) | 57.0°F (2020) | 0.97 in (2007) |
| August 6 | 95.0°F (2022) | 55.9°F (2004) | 0.81 in (2000) |
| August 7 | 95.0°F (2001) | 57.9°F (2004) | 1.03 in (1998) |
| August 8 | 93.9°F (2001) | 59.0°F (2017) | 0.29 in (2011) |
| August 9 | 95.0°F (2001) | 57.0°F (1999) | 0.46 in (2007) |
| August 10 | 93.9°F (2021) | 57.0°F (2024) | 1.11 in (2006) |
| August 11 | 93.9°F (2002) | 55.0°F (2004) | 1.16 in (2014) |
| August 12 | 91.9°F (2002) | 51.1°F (2004) | 2.21 in (2016) |
| August 13 | 93.0°F (2010) | 54.0°F (2004) | 0.93 in (2011) |
| August 14 | 90.0°F (2015) | 54.0°F (2004) | 1.96 in (2023) |
| August 15 | 93.0°F (2000) | 54.0°F (2004) | 0.83 in (2007) |
| August 16 | 96.1°F (2025) | 55.9°F (2004) | 1.27 in (2024) |
| August 17 | 90.0°F (2015) | 59.0°F (2012) | 1.58 in (2025) |
| August 18 | 88.0°F (2025) | 57.0°F (2012) | 1.42 in (2016) |
| August 19 | 88.0°F (2005) | 57.9°F (1997) | 1.33 in (2007) |
| August 20 | 93.0°F (2010) | 59.0°F (2001) | 1.01 in (2016) |
| August 21 | 97.0°F (2003) | 57.0°F (1997) | 1.29 in (2014) |
| August 22 | 90.0°F (2007) | 55.0°F (1997) | 3.17 in (2014) |
| August 23 | 98.1°F (2023) | 55.9°F (1997) | 1.96 in (2007) |
| August 24 | 100.0°F (2023) | 57.0°F (2009) | 0.62 in (1999) |
| August 25 | 97.0°F (2003) | 53.1°F (2017) | 0.80 in (2001) |
| August 26 | 95.0°F (2018) | 48.9°F (2014) | 3.66 in (2012) |
| August 27 | 99.0°F (2024) | 55.9°F (2015) | 1.19 in (2009) |
| August 28 | 95.0°F (2020) | 60.1°F (2004) | 1.26 in (2004) |
| August 29 | 93.0°F (2010) | 55.9°F (2009) | 0.48 in (2022) |
| August 30 | 96.1°F (2013) | 51.1°F (2009) | 0.47 in (2013) |
| August 31 | 93.9°F (2000) | 48.9°F (2009) | 1.07 in (2018) |