September Weather in Skien, Norway

Last updated: August 27, 2025

In Skien, Norway, September experiences a dynamic interplay of weather, featuring a maximum temperature peaking at 25°C (77°F) and an average of 12°C (54°F). As autumn begins to set in, temperatures can dip to a minimum of 1°C (35°F), creating a crisp atmosphere. This month also brings considerable precipitation, with a total of 126 mm (4.9 in) spread over approximately 12 days, resulting in an humidity level of 86%. Nature comes alive with vibrant hues, making September a visually stunning yet variable month in Skien.

September Temperature in Skien

September in Skien, Norway marks a transition into the gentle embrace of autumn, with temperatures reflecting this seasonal shift. The month features mild days, as daytime highs average around 25°C (77°F), perfect for enjoying the outdoor scenery before the chill sets in. Nighttime brings a cooler minimum of 1°C (35°F), hinting at the approaching winter. Overall, the average temperature settles at a comfortable 12°C (54°F), making it an ideal month for outdoor activities and appreciating the vibrant autumn foliage. As September unfolds, residents and visitors alike relish the balance between warm days and crisp nights, a delightful farewell to summer's warmth.

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

The chart illustrates September temperature patterns in Skien, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Skien, September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec292934415160636054453730
Data source: Temperature data for Skien generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Skien

In September, Skien, Norway, experiences a notable shift in precipitation, with an average of 126 mm (4.9 in) of rainfall over 12 days. This marks a substantial increase from the preceding summer months, highlighting the transition into a wetter autumn. The rainfall in September is the highest of the year thus far, overshadowing even the typically rain-soaked July and August. As the days grow shorter and the temperatures dip, Skien's landscape transforms under the lush, rain-fed greenery, showcasing the region's resilience and beauty amid the changing seasons. With each rain shower, the move toward October becomes more pronounced, as the average precipitation continues to rise, ultimately peaking at 139 mm (5.5 in).

September Precipitation Trends in Skien

The chart displays monthly precipitation patterns in Skien, 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. In Skien, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec77818141909610897126139120136
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Skien

As September rolls in Skien, Norway, the humidity begins to rise again, reaching 86%, a noticeable increase from the 78% experienced in August. This shift marks a transition period as the summer warmth fades, with the air feeling increasingly damp as autumn sets in. Overall, the trend depicts a gradual decline in humidity from January through May, with levels stabilizing in the summer months, only to see a resurgence in late summer and early autumn. As Skien prepares for the chill of October—where humidity spikes back to 92%—September serves as a gentle reminder of nature's rhythm, as the days grow shorter and the air turns crisp.

September Average Humidity in Skien

This chart illustrates the average monthly humidity levels in Skien, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Skien is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec93%91%88%83%75%74%74%78%86%92%92%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Skien

As September unfolds in Skien, Norway, the UV Index settles at 4, indicating a moderate level of sun exposure. This marks a transition as the summer months recede; following the high intensity of July and August's UV levels of 7—where sun safety became a necessity—it’s a reminder to remain vigilant. With a burn time of approximately 30 minutes, cautious sun exposure is recommended. September’s conditions encourage outdoor activities while still necessitating sun protection strategies to safeguard against UV rays. As the season shifts towards autumn, understanding these trends is essential for enjoying the remaining days of warmth. For detailed UV forecasts, visit Skien UV Index.

Maximum UV Index Levels in Skien for September

The chart shows the monthly maximum UV Index (UVI) for Skien 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. In September, the maximum UV index in Skien typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec113457754211
Data source: Skien 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 Skien

As September unfolds in Skien, Norway, the landscape begins to transition, showcasing a notable decline in sunshine as the summer warmth wanes. With 284 hours of daylight, September still benefits from a generous amount of sun, although it marks a significant drop from the vibrant 472 hours of July. This gradual decrease highlights the steady shift towards autumn, with each month from May through August boasting impressive sunshine hours, peaking in mid-summer. As the days grow shorter, Skien's natural beauty takes on a different charm, inviting both locals and visitors to enjoy the crisp air and vibrant fall colors, while reminiscing about the sun-drenched days of summer.

Monthly Sunshine Duration in Skien: September Highlighted

The September sunshine duration represents the total number of hours Skien 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.
JanFebMarAprMayJunJulAugSepOctNovDec96h180h287h369h420h456h472h407h284h233h133h98h
Data source: Skien September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Skien During September

In Skien, Norway, the likelihood of sunny weather takes a noticeable dip in September, where the chance of sun drops to a modest 26%. This trend marks a significant decline from the brighter days of April, which boasts a sunny probability of 59%. The sunshine outlook remains variable throughout the summer months, with July and August hovering around the 40% mark. However, as autumn approaches, the clear skies give way to cloudier days, reflected in September's lower percentages. As the year progresses toward winter, the chances of sun continue to wane, reinforcing the idea that September is the onset of a more overcast climate in Skien.

Percentage of Sunny Days in September in Skien

The chart illustrates the percentage of sunny days in Skien 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 Skien experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec37%44%44%59%27%37%41%40%26%30%25%26%
Data source: Skien September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Skien in September

As summer fades into autumn, September in Skien, Norway brings a gentle transition in daylight hours, offering about 12 hours of light. Following the peak of 18 hours in June, this gradual reduction marks the beginning of shorter days, a trend that continues into the darker months of the year. Compared to the robust 17 hours in May and July, the daylight in September reflects the inevitable shift toward winter, yet it still provides ample opportunity for outdoor exploration. As the vibrant hues of autumn foliage emerge, residents and visitors alike can enjoy the pleasant balance of day and night, before the days dwindle to 10 hours in October and eventually down to a mere 6 hours by December.

Average Daylight Hours in Skien for September

The chart illustrates the variation in daylight duration in Skien throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec7h9h 14m11h 52m14h 32m17h18h 24m17h 39m15h 22m12h 46m10h 7m7h 39m6h 14m
Data source: Skien daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Skien

As September unfolds in Skien, Norway, the gentle caress of wind graces the landscape with an average speed of 2.4 m/s (5 mph), mirroring the tranquility of the late summer months. This slight dip in wind speed from the previous months hints at the transition into autumn, where winds begin to gather strength. Although lingering warmth lingers in the air, a gradual increase is anticipated in October, where a brisk 3.1 m/s (7 mph) signals the forthcoming chill. Observing the year, it’s clear that the wind dances lightly during the summer and early autumn, only to pick up pace as winter approaches, inviting a refreshing shift in both weather and scenery.

Average September Wind Speed in Skien

The chart displays monthly wind speed patterns in Skien, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.82.72.72.92.42.22.22.42.4 m/s3.12.72.7
Data source: Skien September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Skien Compares to Other Months

Weather in Skien varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Skien, focusing on differences in temperature, rainfall, humidity, and UV levels.

September and January present strikingly different weather conditions. In September, temperatures range from a chilly 1°C (35°F) at night to a comfortable 25°C (77°F) during the day, with an average of 12°C (54°F). The month experiences considerable rainfall, accumulating 126 mm (4.9 in) over about 12 days, and the humidity hovers around 86%, often making the air feel quite muggy.

In contrast, January brings much colder temperatures, with lows plummeting to -15°C (5°F) and highs only reaching up to 10°C (50°F), averaging -2°C (29°F). Precipitation is lower at 77 mm (3.0 in) across about 9 days, yet the humidity remains high at 93%, resulting in a crisp and biting cold. For more detailed weather information, you can check out Skien weather in January.

September and February present starkly contrasting weather patterns. In September, temperatures typically range from a minimum of 1°C (35°F) to a pleasant maximum of 25°C (77°F), with an average of 12°C (54°F). The month experiences considerable rainfall, totaling 126 mm (4.9 in) over approximately 12 days, accompanied by a humidity level of 86%. In contrast, February brings a much colder climate, with temperatures ranging from a minimum of -16°C (4°F) to a maximum of 11°C (52°F), averaging -2°C (30°F). Despite lower precipitation at 81 mm (3.2 in) across 11 days, the humidity remains high at 91%. This drastic difference in temperature and overall conditions reflects the transition from late summer to midwinter in the region. For more details on February weather, you can visit Skien weather in February.

September and March exhibit distinct weather characteristics. In September, temperatures range from a cool 1°C (35°F) at night to a warm 25°C (77°F) during the day, with an average temperature of 12°C (54°F). The month experiences significant rainfall, accumulating to 126 mm (4.9 in) over approximately 12 days, with humidity levels hovering around 86%. Conversely, March is considerably colder, with minimum temperatures dropping to -16°C (3°F) and maximum temperatures reaching just 15°C (58°F), averaging 1°C (34°F). Although precipitation in March is lower at 81 mm (3.2 in) across about 10 days, humidity is slightly higher at 88%. For a more detailed look at March weather, visit Skien weather in March.

In comparing the weather between September and April, September tends to be milder, with average temperatures ranging from a chilly 1°C (35°F) at night to a warm 25°C (77°F) during the day. The month experiences more precipitation, with an average of 126 mm (4.9 in) across about 12 days, contributing to a humid atmosphere at 86%. In contrast, April is significantly cooler, with temperatures dipping as low as -11°C (12°F) and peaking at a maximum of 22°C (71°F). This month sees much less rainfall, with only 41 mm (1.6 in) over approximately 7 days, along with a slightly lower humidity level of 83%. The transition from the crisp chill of April to the relatively warm September days highlights the seasonal shift as spring gives way to autumn. For a detailed look at April weather, visit Skien weather in April.

When comparing the weather in September and May, we see notable differences in temperature, precipitation, and humidity. September boasts a warmer average temperature of 12°C (54°F), with highs reaching 25°C (77°F), while May has a slightly cooler average of 10°C (51°F) and a maximum temperature of 27°C (82°F). However, May introduces chillier minimum temperatures, dipping to -5°C (23°F), compared to September's mild minimum of 1°C (35°F).

In terms of precipitation, September receives more rainfall, with 126 mm (4.9 in) over 12 days, while May has 90 mm (3.5 in) across 11 days. The humidity is noticeably higher in September at 86%, compared to May's 75%. For those interested in more detailed weather specifics for May, you can visit Skien weather in May.

When comparing the weather in September and June, notable differences emerge in both temperature and humidity. September experiences a wider temperature range with a minimum of 1°C (35°F) and a maximum of 25°C (77°F), while June starts slightly warmer with a minimum of 3°C (38°F) and peaks at 29°C (84°F). The average temperature in September is 12°C (54°F), contrasting with June's more comfortable 16°C (60°F). In terms of precipitation, September sees more rain, with 126 mm (4.9 in) over 12 days, compared to June's 96 mm (3.8 in) spread over 11 days. Additionally, September has a higher humidity level at 86%, making it feel warmer and more muggy compared to June's 74% humidity. For a closer look at June weather specifics, visit Skien weather in June.

Comparing the weather in September and July reveals distinct seasonal characteristics. In July, temperatures range from a minimum of 7°C (44°F) to a maximum of 30°C (87°F), with an average of 17°C (63°F). The month experiences relatively lower humidity at 74% and precipitation totaling 108 mm (4.2 in) over 12 days. In contrast, September sees cooler temperatures, with a minimum of 1°C (35°F), an average of 12°C (54°F), and a maximum of 25°C (77°F). The humidity rises to 86%, alongside increased precipitation of 126 mm (4.9 in), also over 12 days. This comparison underscores a significant drop in temperature and an increase in humidity and rainfall as summer transitions into fall. For more details on July weather, visit Skien weather in July.

In comparing the weather between September and August, we can see distinct differences. September experiences cooler temperatures, with a minimum of 1°C (35°F) compared to August's minimum of 4°C (40°F). The average temperature in September is 12°C (54°F), which is also lower than August's average of 15°C (60°F), though both months share similar maximum temperatures, with September peaking at 25°C (77°F) and August at 26°C (78°F). Additionally, September has more precipitation, totaling 126 mm (4.9 in) over 12 days, while August records 97 mm (3.8 in) across 13 days, reflecting slightly drier weather despite more rain in September. Humidity is higher in September at 86% compared to 78% in August. For a more detailed look at August's climate, check out Skien weather in August.

September and October bring notable shifts in weather patterns. In September, temperatures range from a minimum of 1°C (35°F) to a maximum of 25°C (77°F), with an average of 12°C (54°F). The month experiences relatively high humidity at 86% and registers about 126 mm (4.9 in) of precipitation over 12 days. Conversely, October sees a drop in the average temperature to 7°C (45°F), with minimums reaching as low as -3°C (27°F) and maximums peaking at 18°C (65°F). Precipitation increases slightly to 139 mm (5.5 in) and occurs over 16 days, while humidity rises to 92%. This transition marks a significant shift towards cooler, wetter, and more humid conditions as we move into fall. For more details on the October climate, you can check Skien weather in October.

September and November present distinct weather patterns as they transition from late summer to late autumn. In September, temperatures range from a mild 1°C (35°F) at night to a pleasant maximum of 25°C (77°F) during the day, with an average of 12°C (54°F). The month experiences about 126 mm (4.9 in) of precipitation over 12 days, accompanied by relatively high humidity at 86%. In contrast, November sees a marked drop in temperatures, averaging only 3°C (37°F), with nighttime lows plunging to -11°C (12°F) and daytime highs reaching 15°C (59°F). Precipitation remains comparable at 120 mm (4.7 in) but occurs over an additional day, and humidity increases to 92%. The chill and increased moisture in November create a noticeably different atmosphere compared to the mild and relatively warm September. For more detailed insights about November weather, visit Skien weather in November.

September and December exhibit stark contrasts in weather characteristics. In September, temperatures range from a minimum of 1°C (35°F) to a maximum of 25°C (77°F), with an average of 12°C (54°F). The month receives about 126 mm (4.9 in) of precipitation over 12 days and maintains a humidity level of 86%. In contrast, December sees much colder conditions, with temperatures dropping significantly to a minimum of -12°C (10°F) and an average of -1°C (30°F), peaking at 10°C (50°F). Precipitation increases to 136 mm (5.4 in) occurring over 16 days, accompanied by higher humidity levels at 92%. The drastic changes between these months highlight the transition from autumnal warmth to the chill of winter. For further details, you can visit Skien weather in December.

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Conclusion: What to Expect From September Weather in Skien

As September arrives in Skien, the weather begins to transition from the warmth of summer to the cooler embrace of autumn. With an average temperature settling at a refreshing 12°C (54°F), the days can still bring delightful warmth, peaking at a cheerful 25°C (77°F), yet nights start to feel brisk with temperatures dipping to 1°C (35°F). This month also sees an increase in rainfall, averaging around 126 mm (4.9 in) over 12 days, contributing to a humidity level of 86% that makes the air feel rich and lively. Compared to the preceding months of summer, September shows a noticeable shift towards cooler and wetter conditions, inviting the beauty of changing leaves and a cozy ambiance. For a deeper dive into Skien's weather patterns, explore Skien Climate.