August weather in Decatur, IA
The average temperature in Decatur in August is 73.9°F (63.9°F–83.8°F). Average precipitation: 4.38 inches.
August is a summer month in Decatur, and is warmer than the annual average of 51.6°F. Daily temperatures swing about 19.9°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 13h 38m. For travel, August is a comfortable month to visit.
Avg High
83.8°F
Avg Low
63.9°F
Precipitation
4.38 in
Daylight
13h 38m
August records in Decatur
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 99.0°F (2012) | 57.0°F (2009) | 2.45 in (2016) |
| August 2 | 98.1°F (2011) | 55.0°F (2009) | 2.06 in (2023) |
| August 3 | 97.0°F (2012) | 55.0°F (2020) | 2.26 in (2004) |
| August 4 | 97.0°F (2002) | 48.0°F (2017) | 1.92 in (2023) |
| August 5 | 98.1°F (2018) | 52.0°F (2020) | 0.34 in (2006) |
| August 6 | 95.0°F (2006) | 53.1°F (2004) | 2.02 in (2014) |
| August 7 | 100.9°F (2012) | 55.9°F (2004) | 1.40 in (2007) |
| August 8 | 93.9°F (2010) | 55.9°F (2017) | 2.41 in (2006) |
| August 9 | 96.1°F (2018) | 53.1°F (2024) | 1.31 in (2009) |
| August 10 | 93.0°F (2010) | 50.0°F (2024) | 0.30 in (2017) |
| August 11 | 93.9°F (2007) | 48.9°F (2004) | 0.50 in (2025) |
| August 12 | 93.0°F (2010) | 46.0°F (2004) | 1.82 in (2024) |
| August 13 | 96.1°F (2022) | 52.0°F (2004) | 2.88 in (2005) |
| August 14 | 93.9°F (2007) | 52.0°F (2013) | 1.00 in (2024) |
| August 15 | 91.9°F (2003) | 48.0°F (2004) | 1.86 in (2014) |
| August 16 | 98.1°F (2003) | 51.1°F (2008) | 3.97 in (2011) |
| August 17 | 99.0°F (2003) | 50.0°F (2012) | 0.55 in (2009) |
| August 18 | 100.9°F (2003) | 50.0°F (2012) | 2.20 in (2015) |
| August 19 | 96.1°F (2003) | 53.1°F (2012) | 1.09 in (2018) |
| August 20 | 100.0°F (2003) | 54.0°F (2012) | 1.78 in (2018) |
| August 21 | 98.1°F (2003) | 51.1°F (2004) | 1.13 in (2017) |
| August 22 | 95.0°F (2012) | 53.1°F (2009) | 0.77 in (2015) |
| August 23 | 95.0°F (2020) | 52.0°F (2009) | 1.06 in (2007) |
| August 24 | 99.0°F (2003) | 51.1°F (2015) | 2.08 in (2007) |
| August 25 | 102.0°F (2003) | 46.9°F (2025) | 0.99 in (2004) |
| August 26 | 102.9°F (2003) | 48.9°F (2025) | 7.90 in (2012) |
| August 27 | 96.1°F (2013) | 55.0°F (2025) | 1.25 in (2014) |
| August 28 | 98.1°F (2000) | 55.0°F (2019) | 1.60 in (2018) |
| August 29 | 95.0°F (2013) | -0.8°F (2008) | 0.97 in (2014) |
| August 30 | 100.9°F (2013) | 46.9°F (2009) | 0.81 in (2011) |
| August 31 | 96.1°F (2000) | 53.1°F (2009) | 1.50 in (2021) |