September weather in Unalaska, AK
The average temperature in Unalaska in September is 49.4°F (44.2°F–54.6°F). Average precipitation: 5.73 inches.
September is a fall month in Unalaska, and is warmer than the annual average of 41.6°F. Daily temperatures swing about 10.4°F between overnight low and afternoon high. Expect about 20 days with precipitation. Daylight averages about 12h 24m. For travel, September is a wet month.
Avg High
54.6°F
Avg Low
44.2°F
Precipitation
5.73 in
Daylight
12h 24m
September records in Unalaska
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 69.1°F (2004) | 37.9°F (1928) | 1.42 in (1935) |
| September 2 | 68.0°F (2015) | 19.0°F (1991) | 0.82 in (2012) |
| September 3 | 70.0°F (1922) | 39.0°F (1991) | 0.76 in (1935) |
| September 4 | 73.0°F (2002) | 32.0°F (1991) | 0.76 in (2007) |
| September 5 | 75.0°F (1947) | 23.0°F (1993) | 1.68 in (1930) |
| September 6 | 73.9°F (1985) | 32.0°F (1991) | 1.80 in (1995) |
| September 7 | 70.0°F (1931) | 35.1°F (1991) | 1.60 in (1996) |
| September 8 | 66.9°F (1994) | 34.0°F (1991) | 1.36 in (2011) |
| September 9 | 66.0°F (1926) | 36.0°F (1991) | 1.25 in (1915) |
| September 10 | 80.1°F (1939) | 30.9°F (1987) | 1.97 in (1994) |
| September 11 | 69.1°F (1936) | 30.9°F (1992) | 1.70 in (2016) |
| September 12 | 73.0°F (1941) | 34.0°F (1992) | 1.38 in (2014) |
| September 13 | 69.1°F (2018) | 27.0°F (1994) | 1.32 in (1929) |
| September 14 | 66.9°F (2024) | 32.0°F (1928) | 1.66 in (1936) |
| September 15 | 72.0°F (2022) | 34.0°F (1987) | 1.00 in (1947) |
| September 16 | 68.0°F (1941) | 30.0°F (1994) | 1.82 in (2003) |
| September 17 | 64.9°F (1941) | 5.0°F (1985) | 1.45 in (2010) |
| September 18 | 68.0°F (1927) | 34.0°F (1990) | 2.18 in (1926) |
| September 19 | 63.0°F (1986) | 32.0°F (1990) | 1.94 in (1998) |
| September 20 | 70.0°F (1927) | 26.1°F (1994) | 1.45 in (1994) |
| September 21 | 66.9°F (1926) | 23.0°F (1994) | 2.00 in (1991) |
| September 22 | 66.0°F (2005) | 24.1°F (1994) | 1.93 in (1984) |
| September 23 | 68.0°F (1932) | 28.0°F (1994) | 2.41 in (1939) |
| September 24 | 64.9°F (1931) | 26.1°F (1994) | 1.78 in (1936) |
| September 25 | 63.0°F (1998) | 32.0°F (1992) | 1.14 in (1952) |
| September 26 | 63.0°F (2015) | 25.0°F (1985) | 1.79 in (1934) |
| September 27 | 73.9°F (2015) | 30.0°F (1996) | 1.31 in (1936) |
| September 28 | 61.0°F (1926) | 30.9°F (1992) | 1.60 in (2005) |
| September 29 | 64.0°F (1919) | 28.9°F (1926) | 1.84 in (1994) |
| September 30 | 62.1°F (1916) | 32.0°F (1933) | 1.42 in (1939) |