August weather in Marietta, IL
The average temperature in Marietta in August is 73.0°F (62.5°F–83.5°F). Average precipitation: 3.21 inches.
August is a summer month in Marietta, and is warmer than the annual average of 51.5°F. Daily temperatures swing about 21°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 13h 37m. For travel, August is a comfortable month to visit.
Avg High
83.5°F
Avg Low
62.5°F
Precipitation
3.21 in
Daylight
13h 37m
August records in Marietta
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 97.0°F (2006) | 57.0°F (2009) | 0.75 in (2024) |
| August 2 | 96.1°F (2006) | 55.0°F (2009) | 0.09 in (2009) |
| August 3 | 99.0°F (2006) | 55.0°F (2009) | 0.84 in (2001) |
| August 4 | 98.1°F (2010) | 52.0°F (2017) | 0.81 in (2017) |
| August 5 | 95.0°F (2005) | 52.0°F (2017) | 2.05 in (2023) |
| August 6 | 95.0°F (2007) | 52.0°F (2004) | 0.86 in (2023) |
| August 7 | 93.9°F (2006) | 52.0°F (2004) | 1.00 in (2023) |
| August 8 | 98.1°F (2012) | 54.0°F (2004) | 0.82 in (2009) |
| August 9 | 93.9°F (2005) | 55.0°F (2024) | 0.28 in (2007) |
| August 10 | 96.1°F (2005) | 52.0°F (2024) | 2.31 in (2015) |
| August 11 | 95.0°F (2010) | 50.0°F (2004) | 0.34 in (2017) |
| August 12 | 93.0°F (2010) | 50.0°F (2004) | 0.62 in (2023) |
| August 13 | 97.0°F (2007) | 46.0°F (2004) | 1.94 in (2016) |
| August 14 | 91.9°F (2010) | 46.0°F (2004) | 0.98 in (2010) |
| August 15 | 95.0°F (2007) | 48.9°F (2013) | 0.08 in (2018) |
| August 16 | 96.1°F (2007) | 51.1°F (2004) | 0.65 in (2024) |
| August 17 | 93.9°F (2003) | 51.1°F (2004) | 1.49 in (2009) |
| August 18 | 89.1°F (2003) | 52.0°F (2012) | 0.51 in (2015) |
| August 19 | 91.0°F (2005) | 52.0°F (2012) | 1.90 in (2002) |
| August 20 | 91.9°F (2007) | 54.0°F (2012) | 0.46 in (2004) |
| August 21 | 93.9°F (2003) | 54.0°F (2012) | 0.91 in (2010) |
| August 22 | 97.0°F (2003) | 52.0°F (2024) | 1.05 in (2017) |
| August 23 | 93.9°F (2007) | 52.0°F (2024) | 4.43 in (2002) |
| August 24 | 95.0°F (2012) | 50.0°F (2015) | 0.69 in (2021) |
| August 25 | 99.0°F (2023) | 48.9°F (2015) | 1.02 in (2007) |
| August 26 | 96.1°F (2014) | 48.9°F (2015) | 1.28 in (2019) |
| August 27 | 102.0°F (2003) | 52.0°F (2015) | 1.50 in (2012) |
| August 28 | 97.0°F (2003) | 52.0°F (2015) | 1.27 in (2009) |
| August 29 | 97.0°F (2013) | 48.0°F (2004) | 2.59 in (2018) |
| August 30 | 91.0°F (2010) | 48.0°F (2004) | 0.65 in (2014) |
| August 31 | 98.1°F (2013) | 46.9°F (2009) | 0.14 in (2001) |