August weather in South Jacksonville, IL
The average temperature in South Jacksonville in August is 74.5°F (63.2°F–85.7°F). Average precipitation: 3.32 inches.
August is a summer month in South Jacksonville, and is warmer than the annual average of 52.8°F. Daily temperatures swing about 22.5°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 13h 34m. For travel, August is a comfortable month to visit.
Avg High
85.7°F
Avg Low
63.2°F
Precipitation
3.32 in
Daylight
13h 34m
August records in South Jacksonville
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 100.9°F (2006) | 57.0°F (2018) | 0.76 in (2021) |
| August 2 | 100.0°F (2006) | 55.9°F (2009) | 0.64 in (2014) |
| August 3 | 100.9°F (2006) | 55.9°F (2021) | 1.15 in (2012) |
| August 4 | 98.1°F (2010) | 54.0°F (2017) | 0.60 in (1948) |
| August 5 | 98.1°F (2008) | 52.0°F (2020) | 1.41 in (2009) |
| August 6 | 95.0°F (2007) | 53.1°F (2020) | 1.04 in (2008) |
| August 7 | 96.1°F (2006) | 57.0°F (2020) | 1.00 in (2014) |
| August 8 | 100.9°F (2007) | 57.0°F (2017) | 1.76 in (2006) |
| August 9 | 97.0°F (2007) | 55.9°F (2017) | 1.69 in (2021) |
| August 10 | 96.1°F (2010) | 53.1°F (2024) | 1.62 in (2023) |
| August 11 | 99.0°F (2010) | 55.0°F (2008) | 1.10 in (2025) |
| August 12 | 98.1°F (2007) | 52.0°F (2011) | 0.42 in (2023) |
| August 13 | 102.9°F (2007) | 55.0°F (2014) | 1.20 in (2005) |
| August 14 | 96.1°F (2010) | 48.9°F (2013) | 1.48 in (2010) |
| August 15 | 100.9°F (2007) | 51.1°F (2013) | 0.60 in (1951) |
| August 16 | 104.0°F (2007) | 55.0°F (2008) | 1.30 in (2024) |
| August 17 | 93.9°F (2025) | 55.0°F (2012) | 1.90 in (2009) |
| August 18 | 93.0°F (2025) | 51.1°F (2012) | 0.58 in (2018) |
| August 19 | 93.9°F (2025) | 52.0°F (2012) | 1.59 in (2015) |
| August 20 | 93.0°F (2019) | 54.0°F (2015) | 1.90 in (1951) |
| August 21 | 93.9°F (2011) | 54.0°F (2015) | 1.58 in (2010) |
| August 22 | 96.1°F (2007) | 52.0°F (2024) | 1.04 in (2017) |
| August 23 | 97.0°F (2023) | 53.1°F (2024) | 0.07 in (2015) |
| August 24 | 98.1°F (2023) | 53.1°F (2015) | 0.74 in (2018) |
| August 25 | 100.0°F (2023) | 52.0°F (2015) | 1.06 in (2018) |
| August 26 | 100.0°F (2023) | 48.0°F (2025) | 2.16 in (2004) |
| August 27 | 96.1°F (2024) | 50.0°F (2025) | 1.19 in (1949) |
| August 28 | 99.0°F (2024) | 53.1°F (2015) | 0.31 in (2004) |
| August 29 | 100.9°F (2007) | 55.0°F (2025) | 1.64 in (2008) |
| August 30 | 95.0°F (2007) | 50.0°F (2009) | 1.77 in (2022) |
| August 31 | 98.1°F (2013) | 51.1°F (2009) | 0.97 in (2024) |