Alaska (Ketchikan)
September
Weather in Alaska for September 2025
Your guide to Alaska weather in September - trends and predictions
In general, the average temperature in Alaska at the beginning of September is 14.9 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 10.7 °F by the end of September.
Alaska experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 447.6 mm.
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Temperatures
Rain 🌧️
More
6
Dry days
24
Rainy days
0
Snow days
13°/9°
Temperatures
14 km/h
Avg max wind
86 %
Avg humidity
Alaska Weather September
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What’s the Weather Like in Alaska This September?
Discover the average temperatures and weather trends across Alaska’s cities this September.
Temperatures trend during September in Alaska
See the weather trend as well as the moving average line
September weather in Alaska day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Overcast | 16° /11° | 4.1 mm | 4 | |
| Sept. 2 | Overcast | 16° /10° | 0 mm | 5 | |
| Sept. 3 |  Cloudy | 15° /9° | 0 mm | 4 | |
| Sept. 4 |  Light rain shower | 16° /10° | 4.9 mm | 4 | |
| Sept. 5 | Light rain shower | 13° /10° | 14.3 mm | 3 | |
| Sept. 6 | Cloudy | 14° /10° | 0.3 mm | 4 | |
| Sept. 7 | Light rain shower | 14° /10° | 0.4 mm | 4 | |
| Sept. 8 | Light rain shower | 15° /10° | 0.2 mm | 4 | |
| Sept. 9 | Overcast | 16° /9° | 0 mm | 4 | |
| Sept. 10 |  Patchy light drizzle | 15° /9° | 3.4 mm | 4 | |
| Sept. 11 |  Moderate rain | 14° /9° | 15.4 mm | 4 | |
| Sept. 12 | Moderate rain | 12° /10° | 13.5 mm | 3 | |
| Sept. 13 |  Mist | 13° /9° | 3.7 mm | 3 | |
| Sept. 14 | Moderate rain | 13° /9° | 23.5 mm | 3 | |
| Sept. 15 | Light rain shower | 13° /8° | 18.6 mm | 3 | |
| Sept. 16 |  Moderate or heavy rain with thunder | 13° /9° | 35.2 mm | 3 | |
| Sept. 17 |  Moderate or heavy rain shower | 11° /9° | 32.2 mm | 3 | |
| Sept. 18 | Light rain shower | 11° /8° | 22.2 mm | 3 | |
| Sept. 19 | Light rain shower | 13° /9° | 7.4 mm | 3 | |
| Sept. 20 | Mist | 12° /7° | 9.8 mm | 3 | |
| Sept. 21 | Moderate rain | 12° /9° | 37.2 mm | 3 | |
| Sept. 22 | Moderate rain | 12° /8° | 23 mm | 3 | |
| Sept. 23 | Moderate or heavy rain shower | 11° /9° | 52.1 mm | 3 | |
| Sept. 24 | Moderate rain | 11° /8° | 18.9 mm | 3 | |
| Sept. 25 | Light rain | 12° /7° | 18.1 mm | 3 | |
| Sept. 26 | Moderate or heavy rain with thunder | 12° /7° | 16.7 mm | 3 | |
| Sept. 27 | Moderate or heavy rain with thunder | 11° /8° | 32.5 mm | 3 | |
| Sept. 28 | Patchy rain possible | 10° /7° | 2.4 mm | 3 | |
| Sept. 29 |  Partly cloudy | 10° /6° | 1.9 mm | 3 | |
| Sept. 30 | Overcast | 9° /6° | 35.8 mm | 3 | |
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Important Notice
Our weather forecast for Alaska in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Alaska forecast closer to your planned date for the most up-to-date weather information.
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Alaska in September - FAQ
What are the expected maximum and minimum temperatures in Alaska during September?
During September, expect a variety of temperatures with highs around 13° and lows near 9°, suitable for diverse activities and preferences.
How much rainfall should be expected in Alaska during September?
Significant rainfall exceeding 447.6 mm is expected in Alaska during September, occurring over more than 24 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Alaska during September?
The average wind speed in Alaska during September is 14 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Alaska
Explore the daily rainfall trends and prepare for Alaskas September weather 💧
Counties in Alaska
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Top locations in Alaska
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AnchorageDenali National ParkFairbanksGlacier Bay National Park and PreserveJuneauKetchikanSitkaSkagwayValdezWhittier
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