September weather in Derby, IA
The average temperature in Derby in September is 62.9°F (49.8°F–76.1°F). Average precipitation: 3.71 inches.
September is a fall month in Derby, and is warmer than the annual average of 48.3°F. Daily temperatures swing about 26.3°F between overnight low and afternoon high. Expect about 9 days with precipitation. Daylight averages about 12h 15m. For travel, September is a comfortable month to visit.
Avg High
76.1°F
Avg Low
49.8°F
Precipitation
3.71 in
Daylight
12h 15m
September records in Derby
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 100.9°F (1913) | 33.1°F (1949) | 2.72 in (1931) |
| September 2 | 100.9°F (1913) | 37.9°F (1946) | 2.95 in (1992) |
| September 3 | 102.0°F (1939) | 36.0°F (1974) | 3.05 in (1961) |
| September 4 | 102.9°F (1913) | 33.1°F (1974) | 2.65 in (1917) |
| September 5 | 102.0°F (1913) | 36.0°F (1962) | 3.14 in (1971) |
| September 6 | 100.0°F (1936) | 36.0°F (1962) | 1.70 in (1965) |
| September 7 | 100.9°F (1939) | 35.1°F (2025) | 1.88 in (2015) |
| September 8 | 102.0°F (1947) | 36.0°F (1986) | 2.05 in (1926) |
| September 9 | 99.0°F (1955) | 37.0°F (1995) | 2.92 in (1989) |
| September 10 | 99.0°F (1927) | 34.0°F (1976) | 3.30 in (2014) |
| September 11 | 102.0°F (1936) | 33.1°F (1997) | 1.65 in (1975) |
| September 12 | 97.0°F (1927) | 32.0°F (1955) | 3.30 in (1972) |
| September 13 | 97.0°F (1939) | 33.1°F (1902) | 8.03 in (1961) |
| September 14 | 98.1°F (1939) | 33.1°F (1974) | 3.70 in (1914) |
| September 15 | 100.0°F (1927) | 30.0°F (2011) | 6.95 in (1992) |
| September 16 | 95.0°F (1931) | 30.9°F (2011) | 1.16 in (2016) |
| September 17 | 97.0°F (1927) | 34.0°F (1900) | 1.80 in (1906) |
| September 18 | 95.0°F (1955) | 30.0°F (1916) | 3.84 in (2022) |
| September 19 | 96.1°F (1948) | 30.9°F (1991) | 3.92 in (1986) |
| September 20 | 93.0°F (1908) | 28.0°F (1918) | 4.50 in (1978) |
| September 21 | 95.0°F (1937) | 28.9°F (1999) | 2.62 in (1931) |
| September 22 | 100.0°F (1937) | 23.0°F (1913) | 1.67 in (2010) |
| September 23 | 90.0°F (1937) | 28.9°F (1983) | 3.35 in (1985) |
| September 24 | 90.0°F (1984) | 28.0°F (1989) | 1.55 in (1930) |
| September 25 | 90.0°F (1956) | 30.9°F (1907) | 1.63 in (1931) |
| September 26 | 93.0°F (1956) | 27.0°F (1912) | 1.70 in (1900) |
| September 27 | 91.9°F (1956) | 26.1°F (1942) | 1.76 in (1916) |
| September 28 | 100.0°F (1953) | 19.9°F (1942) | 1.50 in (1911) |
| September 29 | 93.0°F (1953) | 23.0°F (1949) | 1.25 in (2019) |
| September 30 | 91.9°F (1952) | 25.0°F (1984) | 4.31 in (1902) |