September is one of the warmer months of the year in Wasilla, with average highs near 10.4°C and lows around 3.2°C (mean 6.8°C). It is a relatively wet time of year, averaging 114 mm of rainfall and 81% relative humidity across the period.
September is one of the warmer months of the year in Wasilla. Across 45 years of records, the warmest September in Wasilla was 2018 — when the month averaged 9.8°C — while the coldest was 1992 at 0.8°C. Typical September days reach 10.4°C with nights near 3.2°C. The long-term trend is warming, about 0.4°C per decade.
September is a relatively wet time of year in Wasilla, averaging 114 mm of rainfall. The wettest September on record was 2012 with 200 mm, while the driest was 2018 at 37 mm.
Relative humidity in Wasilla during September averages 81%. The most humid September was 2024 at 88%, and the least humid was 2010 at 75%.
September receives about 2.4 kWh/m²/day of solar energy in Wasilla. The sunniest Septembers were 2010 and 2018 at 3 kWh/m²/day, and the cloudiest were 1990 and 2012 at 1.9.
Average wind speed in Wasilla during September is 0.9 m/s. The windiest September was 2012 at 1.4 m/s, while the calmest were 2015 and 2018 at 0.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 6.2°C | 6.3°C | 6.9°C | 7.6°C | 7.1°C | +0.9°C |
| Avg High | 9.9°C | 9.9°C | 10.5°C | 11.2°C | 10.4°C | +0.5°C |
| Avg Low | 2.5°C | 2.7°C | 3.3°C | 4.0°C | 3.8°C | +1.3°C |
| Avg Rain | 98 mm | 116 mm | 116 mm | 114 mm | 128 mm | +30 mm |
September temperatures in Wasilla have risen by about 1.2°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -12.2°C (1992) to a record high of 19.7°C (1996).
Rainfall in September is a relatively wet time of year, averaging 114 mm, with a wettest year of 200 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.3°C per decade while lows rose 0.5°C per decade, narrowing the gap between day and night.
One of the best times to visit Wasilla
September is one of the best times to visit Wasilla. Expect days averaging 10.4°C and nights around 3.2°C (mean 6.8°C) — warmer than Wasilla's yearly average — with higher rainfall (114 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 11.6°C | 8.5°C | 5.3°C | 15.6°C | 1.7°C | 170 mm | 87% | 0.8 m/s | 2.3 |
| 2024 | 10.3°C | 7.2°C | 4.1°C | 13.9°C | 0.0°C | 145 mm | 88% | 0.8 m/s | 2.2 |
| 2023 | 9.7°C | 6.4°C | 3.2°C | 13.9°C | -0.5°C | 112 mm | 84% | 0.8 m/s | 2.4 |
| 2022 | 10.4°C | 7.3°C | 4.2°C | 14.1°C | 1.4°C | 148 mm | 87% | 0.9 m/s | 2.1 |
| 2021 | 9.1°C | 5.4°C | 1.7°C | 15.1°C | -7.2°C | 90 mm | 82% | 0.9 m/s | 2.4 |
| 2020 | 11.3°C | 7.8°C | 4.2°C | 15.2°C | 0.2°C | 104 mm | 80% | 0.9 m/s | 2.3 |
| 2019 | 12.0°C | 8.7°C | 5.4°C | 17.4°C | -2.0°C | 135 mm | 81% | 0.8 m/s | 2.1 |
| 2018 🔥 | 14.1°C | 9.8°C | 5.6°C | 18.4°C | 2.6°C | 37 mm | 77% | 0.7 m/s | 3 |
| 2017 | 10.7°C | 7.6°C | 4.4°C | 14.4°C | 0.6°C | 129 mm | 84% | 1 m/s | 2.1 |
| 2016 | 11.6°C | 8.1°C | 4.7°C | 19.2°C | -0.3°C | 122 mm | 79% | 0.9 m/s | 2.4 |
| 2015 | 8.9°C | 5.4°C | 2.0°C | 15.3°C | -5.3°C | 163 mm | 80% | 0.7 m/s | 2.4 |
| 2014 | 11.3°C | 7.5°C | 3.7°C | 14.2°C | -3.8°C | 96 mm | 80% | 0.9 m/s | 2.5 |
| 2013 | 10.2°C | 6.7°C | 3.1°C | 15.8°C | -4.6°C | 151 mm | 82% | 1 m/s | 2.2 |
| 2012 🌧️ | 9.1°C | 6.2°C | 3.2°C | 13.6°C | -4.5°C | 200 mm | 80% | 1.4 m/s | 1.9 |
| 2011 | 10.6°C | 7.2°C | 3.9°C | 15.1°C | 0.2°C | 66 mm | 79% | 1 m/s | 2.2 |
| 2010 | 13.0°C | 8.5°C | 4.0°C | 18.1°C | -4.6°C | 38 mm | 75% | 0.8 m/s | 3 |
| 2009 | 11.3°C | 7.5°C | 3.8°C | 18.0°C | -3.5°C | 70 mm | 78% | 0.8 m/s | 2.4 |
| 2008 | 9.6°C | 6.5°C | 3.3°C | 13.5°C | -2.4°C | 125 mm | 82% | 0.9 m/s | 2.2 |
| 2007 | 10.8°C | 7.6°C | 4.3°C | 15.3°C | 0.7°C | 93 mm | 81% | 0.8 m/s | 2.4 |
| 2006 | 10.7°C | 7.3°C | 4.0°C | 16.5°C | -4.1°C | 116 mm | 83% | 0.9 m/s | 2.4 |
| 2005 | 11.0°C | 8.0°C | 4.9°C | 14.8°C | 1.8°C | 166 mm | 85% | 0.9 m/s | 2.3 |
| 2004 | 8.9°C | 4.7°C | 0.4°C | 14.2°C | -7.1°C | 172 mm | 76% | 0.8 m/s | 2.6 |
| 2003 | 10.8°C | 6.5°C | 2.2°C | 15.3°C | -4.1°C | 69 mm | 76% | 0.8 m/s | 2.8 |
| 2002 | 10.5°C | 7.3°C | 4.1°C | 15.4°C | -1.3°C | 133 mm | 84% | 0.9 m/s | 2.3 |
| 2001 | 11.5°C | 7.7°C | 3.9°C | 15.6°C | 0.7°C | 108 mm | 82% | 0.8 m/s | 2.5 |
| 2000 | 9.4°C | 5.5°C | 1.6°C | 13.2°C | -6.2°C | 104 mm | 79% | 0.8 m/s | 2.5 |
| 1999 | 10.1°C | 6.6°C | 3.0°C | 15.0°C | -2.3°C | 120 mm | 82% | 0.9 m/s | 2.5 |
| 1998 | 10.0°C | 6.7°C | 3.5°C | 13.1°C | -2.0°C | 95 mm | 80% | 0.8 m/s | 2.5 |
| 1997 | 12.0°C | 8.3°C | 4.6°C | 16.7°C | -1.3°C | 82 mm | 79% | 0.9 m/s | 2.5 |
| 1996 | 9.5°C | 5.4°C | 1.3°C | 19.7°C | -6.1°C | 92 mm | 77% | 0.9 m/s | 2.4 |
| 1995 | 12.3°C | 9.1°C | 5.9°C | 15.8°C | 0.5°C | 123 mm | 84% | 1 m/s | 2.1 |
| 1994 | 10.3°C | 6.3°C | 2.2°C | 15.8°C | -3.8°C | 84 mm | 78% | 0.9 m/s | 2.7 |
| 1993 | 9.3°C | 6.0°C | 2.6°C | 14.2°C | -3.4°C | 191 mm | 84% | 1 m/s | 2.4 |
| 1992 ❄️ | 5.2°C | 0.8°C | -3.5°C | 13.0°C | -12.2°C | 79 mm | 80% | 0.8 m/s | 2.6 |
| 1991 | 10.5°C | 7.2°C | 3.9°C | 14.7°C | -0.3°C | 129 mm | 83% | 1.1 m/s | 2.3 |
| 1990 | 9.7°C | 6.3°C | 3.0°C | 15.3°C | -2.4°C | 170 mm | 84% | 1 m/s | 1.9 |
| 1989 | 10.9°C | 7.7°C | 4.5°C | 15.3°C | 0.8°C | 137 mm | 85% | 0.9 m/s | 2.2 |
| 1988 | 9.9°C | 6.1°C | 2.3°C | 13.8°C | -4.2°C | 95 mm | 81% | 0.8 m/s | 2.6 |
| 1987 | 9.0°C | 5.5°C | 2.1°C | 12.6°C | -4.6°C | 128 mm | 82% | 1 m/s | 2.2 |
| 1986 | 11.0°C | 7.1°C | 3.1°C | 17.7°C | -4.9°C | 56 mm | 77% | 0.8 m/s | 2.6 |
| 1985 | 9.3°C | 5.6°C | 1.9°C | 15.2°C | -3.8°C | 94 mm | 80% | 1 m/s | 2.5 |
| 1984 | 11.7°C | 7.5°C | 3.2°C | 15.7°C | -1.4°C | 68 mm | 77% | 0.8 m/s | 2.6 |
| 1983 | 8.3°C | 4.4°C | 0.5°C | 14.1°C | -8.7°C | 70 mm | 77% | 0.9 m/s | — |
| 1982 | 9.3°C | 6.1°C | 3.0°C | 12.8°C | -0.8°C | 142 mm | 83% | 1 m/s | — |
| 1981 | 9.4°C | 5.5°C | 1.7°C | 14.8°C | -7.1°C | 97 mm | 82% | 0.8 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 10.4°C with lows near 3.2°C (mean 6.8°C), based on 45 years of NASA POWER data.
September averages 114 mm of rainfall in Wasilla, a relatively wet time of year. The wettest on record was 200 mm in 2012.
The hottest September reached 19.7°C in 1996. The coldest dipped to -12.2°C in 1992.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.2°C. Daytime highs moved from 9.6°C to 10.2°C and overnight lows from 2.1°C to 3.7°C over the same span.
September is one of the warmer months of the year in Wasilla and a relatively wet time of year, so plan for around 10.4°C daytime highs and 3.2°C at night.
Not quite — September is the 9th coolest month in Wasilla, averaging 6.8°C.
For September in Wasilla, pack warm layers and a jacket for chilly mornings, with typical highs of 10.4°C and lows of 3.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 81% — quite humid.
Average wind speed in September is 0.9 m/s. The windiest September on record averaged 1.4 m/s (2012).
The wettest September on record was 2012 with 200 mm. On average, September sees 114 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Wasilla behaves each September, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for September specifically, along with year-by-year records and how the month has changed over the decades.
