September weather in Merrill, WI
The average temperature in Merrill in September is 58.0°F (46.3°F–69.7°F). Average precipitation: 3.86 inches.
September is a fall month in Merrill, and is warmer than the annual average of 42.1°F. Daily temperatures swing about 23.4°F between overnight low and afternoon high. Expect about 13 days with precipitation. Daylight averages about 12h 18m. For travel, September is a comfortable month to visit.
Avg High
69.7°F
Avg Low
46.3°F
Precipitation
3.86 in
Daylight
12h 18m
September records in Merrill
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 95.0°F (1937) | 30.9°F (1909) | 3.11 in (1922) |
| September 2 | 95.0°F (1913) | 32.0°F (1974) | 1.88 in (1937) |
| September 3 | 93.9°F (1929) | 27.0°F (1974) | 1.59 in (2019) |
| September 4 | 95.0°F (2023) | 30.0°F (1974) | 1.06 in (2011) |
| September 5 | 93.9°F (1933) | 30.9°F (1974) | 4.64 in (2018) |
| September 6 | 95.0°F (1933) | 32.0°F (1924) | 1.48 in (1990) |
| September 7 | 91.0°F (1913) | 30.0°F (1986) | 3.43 in (2015) |
| September 8 | 97.0°F (1933) | 30.0°F (1979) | 1.73 in (1985) |
| September 9 | 93.9°F (1906) | 27.0°F (1975) | 3.40 in (1938) |
| September 10 | 97.0°F (1931) | 28.0°F (1917) | 1.30 in (1970) |
| September 11 | 95.0°F (1931) | 28.0°F (1943) | 1.86 in (2000) |
| September 12 | 91.9°F (1931) | 28.9°F (1955) | 1.95 in (1975) |
| September 13 | 93.0°F (1927) | 28.9°F (1923) | 2.03 in (1962) |
| September 14 | 91.0°F (1927) | 25.0°F (1923) | 3.95 in (1993) |
| September 15 | 93.9°F (1939) | 27.0°F (2007) | 3.48 in (1967) |
| September 16 | 90.0°F (1948) | 27.0°F (2007) | 2.01 in (2010) |
| September 17 | 87.1°F (1948) | 28.0°F (1959) | 2.09 in (1997) |
| September 18 | 89.1°F (1955) | 27.0°F (1916) | 1.98 in (1942) |
| September 19 | 88.0°F (1908) | 30.0°F (1929) | 3.75 in (1907) |
| September 20 | 89.1°F (1908) | 21.9°F (1973) | 1.95 in (1983) |
| September 21 | 90.0°F (1908) | 21.0°F (1974) | 2.45 in (1980) |
| September 22 | 93.9°F (1937) | 18.0°F (1974) | 1.23 in (2016) |
| September 23 | 93.0°F (1937) | 26.1°F (1995) | 1.42 in (2010) |
| September 24 | 88.0°F (1935) | 19.9°F (1976) | 2.46 in (2010) |
| September 25 | 88.0°F (2017) | 24.1°F (1947) | 1.18 in (1934) |
| September 26 | 88.0°F (1908) | 24.1°F (1941) | 2.58 in (1972) |
| September 27 | 82.9°F (1923) | 25.0°F (1991) | 3.28 in (1959) |
| September 28 | 84.9°F (1923) | 23.0°F (1942) | 1.22 in (1947) |
| September 29 | 84.0°F (1922) | 21.0°F (1949) | 0.71 in (1919) |
| September 30 | 84.0°F (1905) | 25.0°F (1924) | 1.38 in (1985) |