Unalaska Weather in September
Average highs run from 58°F on September 1 to 51°F on September 30, and lows from 47°F to 42°F. Normal precipitation for the month is 5.73 in over about 20 wet days.
September day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
September at a glance
- Average high
- 55°F
- Average low
- 44°F
- Precipitation
- 5.73 in
- Record high
- 80°FSep 10, 1939
- Record low
- 23°FSep 5, 1993
- Chance of a freeze
- 15%
- Daylight
- 13 h 41 min to 11 h 37 min
- Cloud cover
- 88%
- Humidity
- 88%
- Dew point
- 44°F
- Wind
- 15.9 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Sep 1 | 58°F | 47°F | 74°F 2026 | 38°F 1928 | 56% | 0% |
| Sep 2 | 58°F | 47°F | 69°F 2026 | 38°F 1986 | 57% | 0% |
| Sep 3 | 58°F | 47°F | 70°F 1922 | 39°F 1991 | 57% | 0% |
| Sep 4 | 57°F | 46°F | 73°F 2002 | 32°F 1991 | 58% | 0% |
| Sep 5 | 57°F | 46°F | 75°F 1947 | 23°F 1993 | 59% | 0% |
| Sep 6 | 57°F | 46°F | 74°F 1985 | 32°F 1991 | 59% | 0% |
| Sep 7 | 57°F | 46°F | 70°F 1931 | 35°F 1991 | 60% | 0% |
| Sep 8 | 56°F | 46°F | 67°F 1994 | 34°F 1991 | 61% | 0% |
| Sep 9 | 56°F | 45°F | 66°F 1926 | 36°F 1991 | 62% | 0% |
| Sep 10 | 56°F | 45°F | 80°F 1939 | 31°F 1987 | 62% | 0% |
| Sep 11 | 56°F | 45°F | 69°F 1936 | 31°F 1992 | 63% | 0% |
| Sep 12 | 56°F | 45°F | 73°F 1941 | 34°F 1992 | 64% | 0% |
| Sep 13 | 55°F | 45°F | 69°F 2018 | 27°F 1994 | 64% | 0% |
| Sep 14 | 55°F | 45°F | 67°F 2024 | 32°F 1928 | 65% | 0% |
| Sep 15 | 55°F | 44°F | 72°F 2022 | 34°F 1987 | 66% | 0% |
| Sep 16 | 55°F | 44°F | 68°F 1941 | 30°F 1994 | 67% | 0% |
| Sep 17 | 54°F | 44°F | 65°F 1941 | 35°F 1994 | 68% | 0% |
| Sep 18 | 54°F | 44°F | 68°F 1927 | 34°F 1990 | 68% | 0% |
| Sep 19 | 54°F | 44°F | 63°F 1986 | 32°F 1990 | 69% | 0% |
| Sep 20 | 54°F | 43°F | 70°F 1927 | 26°F 1994 | 70% | 0% |
| Sep 21 | 53°F | 43°F | 67°F 1926 | 23°F 1994 | 70% | 0% |
| Sep 22 | 53°F | 43°F | 66°F 2005 | 24°F 1994 | 71% | 0% |
| Sep 23 | 53°F | 43°F | 68°F 1932 | 28°F 1994 | 72% | 0% |
| Sep 24 | 53°F | 43°F | 65°F 1931 | 26°F 1994 | 72% | 0% |
| Sep 25 | 52°F | 42°F | 63°F 1998 | 32°F 1992 | 73% | 0% |
| Sep 26 | 52°F | 42°F | 63°F 2015 | 25°F 1985 | 73% | 0% |
| Sep 27 | 52°F | 42°F | 74°F 2015 | 30°F 1996 | 74% | 0% |
| Sep 28 | 52°F | 42°F | 61°F 1926 | 31°F 1992 | 75% | 0% |
| Sep 29 | 51°F | 42°F | 64°F 1919 | 29°F 1926 | 75% | 0% |
| Sep 30 | 51°F | 42°F | 62°F 1916 | 32°F 1933 | 76% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (AKDT).
- September 1
- sunrise 8:15 AM, sunset 9:56 PM
- September 30
- sunrise 9:07 AM, sunset 8:44 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00502587 (Dutch Harbor), public domain. Records: NOAA GHCN-Daily, station USC00502587, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.