August weather in Big Rock, IL
The average temperature in Big Rock in August is 70.9°F (59.5°F–82.2°F). Average precipitation: 3.35 inches.
August is a summer month in Big Rock, and is warmer than the annual average of 49.4°F. Daily temperatures swing about 22.7°F between overnight low and afternoon high. Expect about 12 days with precipitation. Daylight averages about 13h 41m. For travel, August is a comfortable month to visit.
Avg High
82.2°F
Avg Low
59.5°F
Precipitation
3.35 in
Daylight
13h 41m
August records in Big Rock
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 96.1°F (2006) | 50.0°F (2019) | 0.81 in (2000) |
| August 2 | 97.0°F (2006) | 48.0°F (2009) | 0.56 in (2011) |
| August 3 | 93.9°F (2012) | 52.0°F (1999) | 1.76 in (2010) |
| August 4 | 93.0°F (2012) | 48.9°F (2020) | 1.75 in (2012) |
| August 5 | 91.9°F (2018) | 45.0°F (2020) | 0.81 in (2000) |
| August 6 | 91.9°F (2022) | 46.9°F (2004) | 0.87 in (2007) |
| August 7 | 93.9°F (2001) | 48.0°F (2004) | 0.75 in (2009) |
| August 8 | 91.0°F (2005) | 48.0°F (2017) | 3.69 in (2007) |
| August 9 | 95.0°F (2005) | 46.9°F (1999) | 0.78 in (2008) |
| August 10 | 91.0°F (2016) | 48.0°F (2024) | 0.82 in (2015) |
| August 11 | 93.0°F (2016) | 45.0°F (2004) | 0.58 in (2014) |
| August 12 | 91.0°F (2010) | 45.0°F (2004) | 0.66 in (2016) |
| August 13 | 90.0°F (2010) | 44.1°F (2004) | 1.81 in (2002) |
| August 14 | 120.9°F (2003) | 44.1°F (2001) | 0.77 in (2023) |
| August 15 | 91.9°F (2025) | 41.0°F (2004) | 0.63 in (2024) |
| August 16 | 93.9°F (2025) | 45.0°F (2004) | 0.65 in (2024) |
| August 17 | 88.0°F (2025) | 48.0°F (2012) | 2.37 in (2025) |
| August 18 | 120.9°F (2003) | 46.9°F (2012) | 1.31 in (2025) |
| August 19 | 89.1°F (2021) | 50.0°F (2020) | 1.05 in (2007) |
| August 20 | 91.9°F (2010) | 48.9°F (2001) | 2.04 in (2022) |
| August 21 | 95.0°F (2003) | 46.0°F (2004) | 0.96 in (2021) |
| August 22 | 89.1°F (2007) | 45.0°F (2004) | 1.82 in (2013) |
| August 23 | 93.9°F (2023) | 48.9°F (2018) | 1.23 in (2011) |
| August 24 | 96.1°F (2023) | 48.9°F (2005) | 1.94 in (1999) |
| August 25 | 93.9°F (2003) | 43.0°F (2017) | 1.45 in (2021) |
| August 26 | 93.0°F (2003) | 44.1°F (2025) | 1.64 in (2012) |
| August 27 | 96.1°F (2024) | 46.0°F (2015) | 1.37 in (2024) |
| August 28 | 93.9°F (2003) | 48.0°F (2023) | 1.02 in (2018) |
| August 29 | 93.0°F (2010) | 48.0°F (2001) | 1.09 in (2015) |
| August 30 | 93.0°F (2013) | 43.0°F (2009) | 1.18 in (2001) |
| August 31 | 93.0°F (2000) | 39.9°F (2009) | 0.24 in (2019) |