September weather in Duncan, OK
The average temperature in Duncan in September is 74.6°F (63.3°F–85.8°F). Average precipitation: 3.79 inches.
September is a fall month in Duncan, and is warmer than the annual average of 61.9°F. Daily temperatures swing about 22.5°F between overnight low and afternoon high. Expect about 7 days with precipitation. Daylight averages about 12h 12m. For travel, September is a comfortable month to visit.
Avg High
85.8°F
Avg Low
63.3°F
Precipitation
3.79 in
Daylight
12h 12m
September records in Duncan
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 107.1°F (1939) | 57.0°F (1968) | 2.10 in (1981) |
| September 2 | 108.0°F (1939) | 54.0°F (1952) | 2.47 in (1979) |
| September 3 | 107.1°F (1939) | 48.9°F (1974) | 1.47 in (1988) |
| September 4 | 108.0°F (2000) | 51.1°F (1974) | 3.40 in (1991) |
| September 5 | 108.0°F (2000) | 51.1°F (1974) | 2.25 in (1937) |
| September 6 | 106.0°F (1998) | 53.1°F (1974) | 1.90 in (1973) |
| September 7 | 107.1°F (1947) | 55.0°F (1950) | 1.29 in (1973) |
| September 8 | 102.9°F (1947) | 53.1°F (1957) | 2.65 in (2018) |
| September 9 | 100.0°F (1938) | 53.1°F (2004) | 3.33 in (1941) |
| September 10 | 100.0°F (1946) | 48.9°F (1962) | 2.11 in (2020) |
| September 11 | 102.0°F (1963) | 52.0°F (1940) | 3.72 in (1992) |
| September 12 | 102.9°F (2000) | 48.9°F (1940) | 1.62 in (1975) |
| September 13 | 100.9°F (2011) | 48.9°F (1960) | 3.50 in (1989) |
| September 14 | 106.0°F (2011) | 45.0°F (1945) | 3.05 in (1993) |
| September 15 | 100.0°F (1956) | 45.0°F (1993) | 2.33 in (1988) |
| September 16 | 102.0°F (1956) | 45.0°F (1993) | 2.15 in (1964) |
| September 17 | 99.0°F (1947) | 46.0°F (1981) | 3.33 in (2006) |
| September 18 | 102.0°F (1952) | 44.1°F (1981) | 1.61 in (2017) |
| September 19 | 100.0°F (1954) | 46.9°F (1991) | 3.00 in (1965) |
| September 20 | 102.9°F (1954) | 39.9°F (1971) | 1.40 in (1942) |
| September 21 | 100.0°F (1944) | 39.0°F (1983) | 1.83 in (2019) |
| September 22 | 99.0°F (1948) | 42.1°F (1999) | 6.22 in (2018) |
| September 23 | 97.0°F (1938) | 41.0°F (1995) | 4.43 in (1970) |
| September 24 | 99.0°F (1939) | 39.9°F (1965) | 2.42 in (1968) |
| September 25 | 97.0°F (1938) | 41.0°F (1989) | 4.00 in (1974) |
| September 26 | 100.9°F (1953) | 41.0°F (2000) | 1.40 in (1945) |
| September 27 | 100.0°F (1953) | 36.0°F (1942) | 3.44 in (2017) |
| September 28 | 102.9°F (1953) | 43.0°F (1996) | 2.62 in (1944) |
| September 29 | 100.0°F (1953) | 44.1°F (1945) | 2.13 in (1945) |
| September 30 | 99.0°F (1977) | 37.9°F (1984) | 2.22 in (1985) |