September Weather in Sitka, United States

Last updated: February 24, 2025

In September, Sitka experiences a captivating transition in weather, characterized by a maximum temperature of 21°C (70°F) and a cool average of 11°C (52°F), dipping to a refreshing minimum of 5°C (42°F). The month is notably wet, with precipitation levels reaching 224 mm (8.8 in) over 17 days, contributing to the lush landscape. With humidity soaring at 94%, outdoor enthusiasts can expect a moody yet enchanting atmosphere, perfect for experiencing the rich natural beauty of this Alaskan gem.

September Temperature in Sitka

As September arrives in Sitka, United States, a noticeable shift in temperatures marks the transition from summer to fall. The month opens with a minimum temperature of 5°C (42°F), gradually moving towards an average of 11°C (52°F) and peaking at a comfortable 21°C (70°F). This slight cooling trend follows the warmer months of August, where highs reached 25°C (77°F), indicating a descent into the cooler autumn season. With each passing day, the air becomes crisper, making September a perfect time to enjoy the breath-taking natural beauty of Sitka as the leaves start their vibrant transformation. The overall mildness of the month, contrasted with the chilly winter temperatures that loom ahead, offers a delightful window for both locals and visitors to relish the stunning landscapes and outdoor activities before the colder months set in.

September Weather in Sitka: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Sitka, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec333235404651555552453836
Data source: Temperature data for Sitka generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Sitka

In September, Sitka experiences a notable surge in precipitation, with an average rainfall of 224 mm (8.8 in) over approximately 17 days. This marks a significant increase from the preceding summer months, with August's 201 mm (7.9 in) of rainfall falling just short of September’s totals. As the transition from summer to autumn begins, September's rainfall sets the stage for an even wetter October, which boasts a formidable 276 mm (10.9 in), suggesting a trend of increasing precipitation as the year progresses. This uptick not only reflects the typical climate patterns of the region but also emphasizes Sitka’s reputation for its lush, misty landscapes shaped by abundant rainfall.

September Precipitation Trends in Sitka

The chart displays monthly precipitation patterns in Sitka, with values for each month alongside September's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec219179179174124137112201224276284293
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Sitka

In September, Sitka experiences a humidity level of 94%, which marks a slight decrease from the peak 100% seen in August. This enduring high humidity aligns with the overall trend in Sitka, where the summer months of June through August consistently showcase elevated moisture levels, peaking in July. As the year transitions into autumn, humidity begins to drop gradually, foreshadowing the return to more moderate levels in October (87%) and beyond. The fluctuating yet high humidity throughout the year reflects Sitka's coastal climate, characterized by damp conditions, particularly during the summer months, making for a unique and lush environment.

September Average Humidity in Sitka

This chart illustrates the average monthly humidity levels in Sitka, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec87%85%83%83%88%95%101%100%94%87%85%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Sitka

As September rolls in Sitka, the UV Index sits at a comfortable 5, indicating a moderate exposure category. This shift from the higher levels seen during the summer months offers a pleasant reprieve, where the risk of harm from unprotected sun exposure remains notable but manageable, with a burn time of about 30 minutes. It’s a great reminder to enjoy the beautiful fall scenery while still keeping skin safety in mind. Looking at the broader yearly trend, Sitka experiences gradually increasing UV levels from low in winter to high during the summer peak, before tapering off again, illustrating the changing seasons and their effects on sun exposure. For more detailed information, visit the full Sitka UV Index.

Maximum UV Index Levels in Sitka for September

The chart shows the monthly maximum UV Index (UVI) for Sitka in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec124566775311
Data source: Sitka September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Sitka

September in Sitka embraces a gentle transition as summer wanes, offering 185 hours of sunshine that softly signals the approach of autumn. Following June and July's peak brightness, Sitka sees a slight reduction in daylight, yet this month still shines brighter than the winter months ahead. The steady decline from 220 hours in July to September's golden rays reflects a consistent yearly trend, where sunshine ebbs gradually as the seasons shift. With September's crisp air and vibrant fall foliage, residents and visitors alike are encouraged to savor the lingering sunshine before the days grow shorter, marking a beautiful end to summer's embrace.

Monthly Sunshine Duration in Sitka: September Highlighted

The September sunshine duration represents the total number of hours Sitka experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec44h128h177h196h220h222h220h212h185h120h64h52h
Data source: Sitka September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Sitka During September

In Sitka, United States, the likelihood of sunny weather follows a noticeable trend throughout the year, with September experiencing one of the lowest chances of sunshine at just 10%. This decline is particularly evident when compared to the more promising conditions in earlier months like February, which boasts a 34% chance of sun. As summer fades, the sunshine probability dwindles further, with July and August also falling short, at 18% and 17%, respectively. This creates a pattern where the dog days of summer rarely extend into autumn, highlighting the need for residents and visitors alike to prepare for a more overcast and unpredictable September.

Percentage of Sunny Days in September in Sitka

The chart illustrates the percentage of sunny days in Sitka throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Sitka experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec15%34%19%33%12%24%18%17%10%16%16%30%
Data source: Sitka September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Sitka in September

As September unfolds in Sitka, the lingering warmth of summer gives way to the onset of autumn, bringing with it 12 hours of daylight. This marks a noticeable decline from the sun-drenched months of June and July, where daylight reached a peak of 17 hours. Following the vibrant days of August with 15 hours, September's sunlight begins to fade, hinting at the shorter days that lie ahead. This gradual transition reflects a clear trend: as the year progresses from the long, bright summer days, Sitka steadily descends into shorter daylight hours, ultimately culminating in the dim, 6-hour days of December. Embracing these shifts, residents of Sitka experience the beauty and rhythm of nature as it prepares for the winter ahead.

Average Daylight Hours in Sitka for September

The chart illustrates the variation in daylight duration in Sitka throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec7h 29m9h 30m11h 54m14h 22m16h 34m17h 46m17h 5m15h 3m12h 40m10h 14m8h 1m6h 47m
Data source: Sitka daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Sitka

As September unfolds in Sitka, United States, the average wind speed experiences a slight uptick, reaching 3.9 m/s (9 mph), a refreshing shift from the more tranquil summer months. After a gradual decline from spring through July, where winds hovered around 2.6 to 3.3 m/s, the arrival of fall brings a gentle breeze that begins to stir the surroundings. This increase signals a transitional period, as the winds prepare to intensify in October, where they climb to 4.4 m/s (10 mph). Overall, the trends of wind patterns in September highlight a subtle yet noteworthy resurgence, as nature whispers of the approaching autumn, inviting residents and visitors to embrace the crisp, invigorating air.

Average September Wind Speed in Sitka

The chart displays monthly wind speed patterns in Sitka, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec4.74.03.72.83.32.82.63.23.9 m/s4.44.13.5
Data source: Sitka September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Sitka Compares to Other Months

The weather in Sitka changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Sitka and find detailed weather information for every month.

September and January present distinct contrasts in weather patterns. September experiences milder temperatures, with average highs reaching 21°C (70°F) and a notable humidity level of 94%, resulting in a lush, damp environment. In contrast, January is characterized by stark cold, with average temperatures plummeting to around 1°C (33°F) and even dipping to a frigid -17°C (2°F) at night. While both months see significant precipitation—224 mm (8.8 in) in September and 219 mm (8.6 in) in January—the winter month has slightly fewer rainy days, contributing to a more snow-dominated landscape. For further details, you can refer to Sitka weather in January.

In comparing the weather of September and February, we see a stark contrast in temperatures and conditions. September experiences milder temperatures, with a minimum of 5°C (42°F) and an average of 11°C (52°F), peaking at 21°C (70°F). The month is also characterized by high humidity at 94% and considerable precipitation of 224 mm (8.8 in) over 17 days. In contrast, February brings much colder weather, with temperatures dropping to a minimum of -16°C (4°F) and averaging around 0°C (32°F), reaching a maximum of just 9°C (48°F). This month sees slightly less precipitation at 179 mm (7.0 in) over 15 days, and the humidity is lower at 85%. For more detailed information, you can check Sitka weather in February.

When comparing the weather in September and March, we see notable differences in temperature and overall climate. September features a mild climate with temperatures ranging from a minimum of 5°C (42°F) to a maximum of 21°C (70°F), accompanied by high humidity at 94%. In contrast, March experiences much colder conditions, with temperatures dipping as low as -13°C (9°F) and averaging just 1°C (35°F). While both months see significant precipitation, September receives more, totaling 224 mm (8.8 in) over 17 days compared to March's 179 mm (7.0 in) across 18 days. For more detailed insights, you can explore Sitka weather in March.

September weather is generally milder than April, with average temperatures ranging from a minimum of 5°C (42°F) to a maximum of 21°C (70°F), compared to April's cooler temperatures of -6°C (21°F) to 14°C (57°F). Despite September's higher average temperatures, it experiences significantly more precipitation, totaling 224 mm (8.8 in) over 17 days, whereas April sees 174 mm (6.9 in) of rain over 18 days. Humidity levels are also higher in September at 94%, compared to 83% in April, resulting in distinctly different atmospheric conditions for these two months. For more detailed weather information in April, you can check out Sitka weather in April.

September and May exhibit distinct weather characteristics, reflecting the transition between seasons. In September, temperatures range from a minimum of 5°C (42°F) to a maximum of 21°C (70°F), with an average of 11°C (52°F). The month is notably wet, with about 224 mm (8.8 in) of precipitation over 17 days and high humidity at 94%. Conversely, May is cooler, with temperatures ranging from a minimum of 1°C (35°F) to a maximum of 20°C (68°F) and an average of 8°C (46°F). The precipitation decreases significantly to 124 mm (4.9 in) across 19 days, and humidity is slightly lower at 88%. For more detailed information, you can check Sitka weather in May.

In comparing the weather of September and June, both months see similar maximum temperatures, peaking at around 21°C (70°F) to 21°C (71°F) respectively. However, September tends to be cooler overall, with an average temperature of 11°C (52°F) compared to June's slightly warmer average of 10°C (51°F). Both months are characterized by high humidity, with September averaging 94% and June at 95%. Precipitation levels are notably higher in September, with 224 mm (8.8 in) falling over 17 days, whereas June experiences only 137 mm (5.4 in) across 20 days. This indicates that while June may have more days of rain, September delivers a heavier total rainfall. For a closer look at June's weather specifics, you can refer to Sitka weather in June.

In comparing the weather between September and July, it's evident that September typically experiences cooler temperatures, with a minimum of 5°C (42°F) and an average of 11°C (52°F), while July offers slightly warmer conditions with minimums of 9°C (48°F) and an average of 13°C (55°F). Precipitation is notably higher in September, totaling 224 mm (8.8 in) over 17 days compared to July's 112 mm (4.4 in) over 15 days. Additionally, September has a higher humidity level at 94%, whereas July's humidity reaches 101%. For those interested in exploring July's weather in more detail, check out Sitka weather in July.

In comparing the weather patterns of September and August, it's clear that September experiences cooler temperatures overall, with a minimum of 5°C (42°F) and a maximum of 21°C (70°F), while August sees slightly warmer conditions, ranging from a minimum of 7°C (45°F) up to a maximum of 25°C (77°F). Additionally, September has higher average precipitation at 224 mm (8.8 in), compared to August's 201 mm (7.9 in), albeit with a similar frequency of rainy days—17 in September versus 20 in August. Interestingly, September's humidity averages 94%, slightly lower than August's 100%, indicating a shift in moisture levels as the summer transitions into autumn. For a detailed look at August's weather, you can refer to Sitka weather in August.

September generally experiences milder temperatures with an average of 11°C (52°F) and a maximum of 21°C (70°F), while October sees a drop in temperature, averaging 7°C (45°F) and peaking at 16°C (60°F). Precipitation increases from 224 mm (8.8 in) over 17 days in September to 276 mm (10.9 in) in October, occurring over 22 days. Additionally, September's humidity is higher at 94%, compared to 87% in October. For more detailed weather information, visit Sitka weather in October.

September and November weather exhibit distinct differences, particularly in temperature and precipitation patterns. September typically enjoys milder temperatures, with averages around 11°C (52°F) and a maximum of 21°C (70°F), while November sees a significant drop, averaging just 4°C (39°F) and reaching a maximum of 12°C (54°F). Additionally, September experiences more humidity at 94%, although November has a lower humidity level of 85%, creating a cooler, crisper feel. Precipitation is notably higher in November, with 284 mm (11.2 in) spread over 23 days compared to September’s 224 mm (8.8 in) over 17 days. This shift in weather highlights the transition from the late-summer warmth of September to the cooler, wetter conditions of November. For more detailed insights, check out Sitka weather in November.

In September, the weather tends to be milder, with temperatures ranging from a minimum of 5°C (42°F) to a maximum of 21°C (70°F) and an average of 11°C (52°F). However, this month also experiences significant precipitation, totaling 224 mm (8.8 in) over 17 days, coupled with high humidity at 94%. In contrast, December brings a stark shift, with much colder temperatures that range from a minimum of -14°C (7°F) to a maximum of 10°C (50°F), averaging just 2°C (36°F). This month sees even more precipitation, reaching 293 mm (11.5 in) across 22 days, though humidity decreases slightly to 87%. For more detailed insights into winter conditions, check out Sitka weather in December.

Compare Sitka's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Sitka

As September arrives in Sitka, the transition into fall becomes evident, characterized by cooler temperatures and increased precipitation compared to the summer months. The average temperature dips, settling around a brisk 11°C (52°F), while the humidity hovers at a notable 94%, creating a fresh, crisp atmosphere. With about half the month seeing rain, September stands out for its frequent precipitation days, far exceeding those of the summer, making it a time to prepare for the wet and chilly season ahead. The lush landscapes benefit from the substantial 224 mm (8.8 in) of rainfall, offering a vibrant display of nature's resilience. For detailed insights into what to expect throughout the year, visit Sitka Climate.