August weather in Johnsburg, IL
The average temperature in Johnsburg in August is 71.0°F (59.7°F–82.3°F). Average precipitation: 3.70 inches.
August is a summer month in Johnsburg, and is warmer than the annual average of 48.6°F. Daily temperatures swing about 22.6°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 13h 43m. For travel, August is a comfortable month to visit.
Avg High
82.3°F
Avg Low
59.7°F
Precipitation
3.70 in
Daylight
13h 43m
August records in Johnsburg
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 95.0°F (2001) | 48.9°F (1998) | 0.48 in (1995) |
| August 2 | 93.9°F (2002) | 50.0°F (2025) | 0.38 in (2014) |
| August 3 | 93.0°F (2006) | 50.0°F (2025) | 1.68 in (1981) |
| August 4 | 91.9°F (2005) | 50.0°F (2020) | 1.33 in (2004) |
| August 5 | 96.1°F (2018) | 46.0°F (2020) | 2.35 in (2007) |
| August 6 | 91.9°F (2018) | 43.0°F (1994) | 1.97 in (1951) |
| August 7 | 93.9°F (2022) | 46.9°F (1994) | 4.19 in (2007) |
| August 8 | 93.0°F (2001) | 51.1°F (1993) | 0.73 in (2011) |
| August 9 | 93.9°F (2001) | 48.0°F (1999) | 1.95 in (1988) |
| August 10 | 95.0°F (2005) | 51.1°F (2024) | 3.90 in (2021) |
| August 11 | 93.9°F (2021) | 51.1°F (2008) | 1.37 in (2014) |
| August 12 | 93.9°F (2021) | 48.0°F (2004) | 1.31 in (2005) |
| August 13 | 95.0°F (1995) | 50.0°F (2017) | 1.06 in (1985) |
| August 14 | 91.9°F (1995) | 45.0°F (2004) | 4.58 in (1987) |
| August 15 | 91.0°F (1995) | 42.1°F (2004) | 3.05 in (1981) |
| August 16 | 91.9°F (2025) | 46.9°F (2004) | 1.58 in (1978) |
| August 17 | 93.9°F (2025) | 48.9°F (2013) | 1.41 in (1997) |
| August 18 | 88.0°F (1995) | 45.0°F (2012) | 1.09 in (1979) |
| August 19 | 88.0°F (2016) | 51.1°F (2020) | 2.59 in (2025) |
| August 20 | 89.1°F (2021) | 51.1°F (1999) | 1.54 in (2007) |
| August 21 | 91.9°F (2023) | 46.9°F (2012) | 0.73 in (2011) |
| August 22 | 93.9°F (2003) | 44.1°F (2004) | 3.80 in (2002) |
| August 23 | 89.1°F (2020) | 48.9°F (1997) | 1.31 in (1998) |
| August 24 | 97.0°F (2023) | 50.0°F (2005) | 2.07 in (2006) |
| August 25 | 98.1°F (2023) | 45.0°F (2017) | 0.98 in (1998) |
| August 26 | 93.9°F (2003) | 46.0°F (2025) | 1.70 in (1987) |
| August 27 | 95.0°F (2024) | 45.0°F (2015) | 1.34 in (1983) |
| August 28 | 98.1°F (2024) | 45.0°F (2015) | 2.55 in (1981) |
| August 29 | 95.0°F (2021) | 46.9°F (2025) | 2.25 in (2018) |
| August 30 | 90.0°F (2010) | 48.9°F (2004) | 0.75 in (2024) |
| August 31 | 91.9°F (2013) | 39.9°F (2009) | 0.72 in (2013) |