Monthly climate guide
Juneau weather in September
Expect cool weather in Juneau in September: afternoons reach about 9°C (48°F), while nights drop to around 5°C (40°F). Around 336 mm of rain falls over the month (very wet), and skies are often cloudy. Daytime highs are 3°C cooler than August and 6°C warmer than October.
What stands out in September
- Temperatures are falling — expect highs around 6°C lower by October.
- Days and nights are close, only about 4°C apart.
- Juneau is usually about 14°C cooler than Milwaukee in September.
- Seasonally, September counts as early autumn in Juneau.
Avg high
9°C
48°F
Avg low
5°C
40°F
Rainfall
336 mm
very wet
Humidity
89%
relative
Sky
79%
cloud · often cloudy
Juneau weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | -5°C / 23°F | -9°C / 15°F | 346 mm | 94% | 78% |
| February | -5°C / 23°F | -11°C / 13°F | 224 mm | 93% | 72% |
| March | -3°C / 26°F | -9°C / 15°F | 171 mm | 90% | 71% |
| April | 1°C / 34°F | -3°C / 26°F | 191 mm | 88% | 77% |
| May | 6°C / 42°F | 2°C / 36°F | 167 mm | 87% | 73% |
| June | 10°C / 50°F | 6°C / 42°F | 165 mm | 87% | 82% |
| July | 13°C / 55°F | 8°C / 46°F | 197 mm | 88% | 80% |
| August | 12°C / 53°F | 8°C / 46°F | 298 mm | 89% | 79% |
| September | 9°C / 48°F | 5°C / 40°F | 336 mm | 89% | 79% |
| October | 3°C / 38°F | -1°C / 31°F | 348 mm | 91% | 79% |
| November | -3°C / 26°F | -8°C / 18°F | 314 mm | 94% | 78% |
| December | -4°C / 24°F | -8°C / 17°F | 353 mm | 95% | 79% |
What to pack for September
- A proper insulated winter coat
- A hat, scarf and gloves
- A compact umbrella or packable rain jacket
- Water-resistant shoes
Is September a good time to visit Juneau?
Compare the months in the chart above to find your ideal window.
Best time to visit Juneau →Other United States cities in September
Cite or embed this data
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Juneau weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/usa/juneau/september
<a href="https://weathercompare.eu/weather/usa/juneau/september">Juneau weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/usa/juneau" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Juneau weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/usa/juneau/september">Juneau weather in September</a> – WeatherCompare</p>
Juneau in September: quick answers
Is September a good time to visit Juneau?
September is cool in Juneau, with highs around 9°C. Better for museums and city walks than the beach, and usually quieter.
How warm is Juneau in September?
Average highs are about 9°C (48°F) and average lows about 5°C (40°F), based on 10 years of daily data.
Does it rain a lot in Juneau in September?
Juneau typically gets around 336 mm of rain in September — very wet.
Figures are long-term averages for the area around Juneau (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.