September weather in Promise City, IA
The average temperature in Promise City in September is 64.7°F (53.5°F–75.9°F). Average precipitation: 4.20 inches.
September is a fall month in Promise City, and is warmer than the annual average of 49.9°F. Daily temperatures swing about 22.4°F between overnight low and afternoon high. Daylight averages about 12h 15m. For travel, September is a comfortable month to visit.
Avg High
75.9°F
Avg Low
53.5°F
Precipitation
4.20 in
Daylight
12h 15m
September records in Promise City
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 100.9°F (1913) | 45.0°F (1915) | 2.21 in (2010) |
| September 2 | 100.0°F (1913) | 48.0°F (1902) | 1.75 in (1918) |
| September 3 | 102.0°F (1913) | 46.0°F (1907) | 0.60 in (1912) |
| September 4 | 102.9°F (1913) | 45.0°F (1902) | 1.25 in (1918) |
| September 5 | 102.0°F (1913) | 42.1°F (1918) | 2.50 in (1914) |
| September 6 | 99.0°F (1913) | 44.1°F (2025) | 1.28 in (1911) |
| September 7 | 97.0°F (1912) | 42.1°F (2025) | 0.61 in (2007) |
| September 8 | 99.0°F (1912) | 45.0°F (2017) | 1.74 in (2019) |
| September 9 | 100.9°F (1912) | 37.9°F (2008) | 2.61 in (1903) |
| September 10 | 99.0°F (2013) | 39.9°F (1999) | 1.85 in (2014) |
| September 11 | 96.1°F (2013) | 42.1°F (1999) | 2.34 in (2010) |
| September 12 | 95.0°F (2000) | 36.0°F (1902) | 2.78 in (1949) |
| September 13 | 91.9°F (1998) | 34.0°F (1902) | 2.50 in (2008) |
| September 14 | 95.0°F (2025) | 37.9°F (2014) | 3.18 in (2010) |
| September 15 | 91.0°F (1906) | 35.1°F (2007) | 0.88 in (1910) |
| September 16 | 93.0°F (1906) | 37.9°F (1903) | 0.62 in (2016) |
| September 17 | 91.0°F (2025) | 35.1°F (1903) | 1.08 in (1906) |
| September 18 | 91.9°F (1910) | 37.0°F (1903) | 2.02 in (2022) |
| September 19 | 91.9°F (1908) | 39.9°F (1902) | 1.15 in (2007) |
| September 20 | 91.9°F (1908) | 30.9°F (1918) | 1.29 in (1948) |
| September 21 | 95.0°F (2022) | 33.1°F (1918) | 1.71 in (2021) |
| September 22 | 90.0°F (2016) | 27.0°F (1913) | 2.73 in (2010) |
| September 23 | 89.1°F (2017) | 35.1°F (1999) | 0.98 in (1910) |
| September 24 | 91.0°F (2017) | 36.0°F (1903) | 1.39 in (2010) |
| September 25 | 90.0°F (2017) | 32.0°F (1907) | 1.00 in (1915) |
| September 26 | 88.0°F (2017) | 30.0°F (1912) | 0.80 in (2005) |
| September 27 | 89.1°F (1905) | 28.0°F (2003) | 3.23 in (2014) |
| September 28 | 88.0°F (2021) | 30.0°F (1908) | 1.40 in (2019) |
| September 29 | 88.0°F (2021) | 27.0°F (1908) | 2.41 in (2019) |
| September 30 | 89.1°F (2023) | 32.0°F (1912) | 2.05 in (2019) |