September Weather in Kolari, Finland

Last updated: August 21, 2025

In Kolari, Finland, September presents a striking transition from summer to autumn. Visitors can expect maximum temperatures around 21°C (71°F), with an average falling to 7°C (46°F), and chilly nights where the mercury can dip to a minimum of -8°C (18°F). The region experiences 67 mm (approximately 2.6 in) of rainfall over 11 days, creating a lush landscape infused with fall colors. With a high humidity of 91%, the atmosphere can feel quite crisp, making it a perfect time for outdoor adventures and embracing the serene beauty of the Finnish wilderness.

September Temperature in Kolari

In September, Kolari, Finland begins to transition from the warmth of summer to the brisk chill of autumn. With minimum temperatures dropping to -8°C (18°F) and average highs reaching a pleasant 21°C (71°F), this month strikes a balance between lingering warmth and the impending coolness. The average temperature settles around 7°C (46°F), making it a refreshing period ideal for enjoying the vibrant fall foliage. As September progresses, one can sense the forthcoming winter, marked by a notable dip in overnight temperatures compared to the balmy summer months. This unique blend of warmth and chill makes September a captivating time in Kolari, where nature's palette shifts dramatically.

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

The chart illustrates September temperature patterns in Kolari, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Kolari, 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).
JanFebMarAprMayJunJulAugSepOctNovDec121222324355605545332417
Data source: Temperature data for Kolari 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 Kolari

In September, Kolari experiences a notable transition as autumn begins to set in, marked by 67 mm (2.6 in) of precipitation over 11 days. This reflects a slight decrease from the 92 mm (3.6 in) recorded in August, yet September still retains a robust amount of rainfall compared to the earlier months of the year. The steady upward trend in precipitation throughout the summer months culminates in September’s substantial totals, as the days grow shorter and the weather transitions. With autumn's arrival, Kolari witnesses a refreshing balance of moisture that prepares the landscape for the cooler months ahead, contrasting the summer's intensity while still maintaining a lively rhythm of rainfall.

September Precipitation Trends in Kolari

The chart displays monthly precipitation patterns in Kolari, 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 Kolari, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec363337334974819267915956
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Kolari

In September, Kolari, Finland, experiences a notable shift in humidity, with levels sitting at 91%. This marks a slight increase from the 87% recorded in August, suggesting a gradual transition towards the wetter autumn months. As summer gives way to fall, humidity tends to fluctuate, reflecting the region's cooling temperatures and the return of more stable moisture patterns. Historically, humidity levels in Kolari peak sharply as winter approaches, with October's readings rising to 96% and November reaching 98%. Thus, September serves as a pivotal month, bridging the drier summer and the increasingly humid fall, indicative of nature’s cyclical rhythm.

September Average Humidity in Kolari

This chart illustrates the average monthly humidity levels in Kolari, 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 Kolari is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec101%99%92%87%82%78%83%87%91%96%98%101%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Kolari

As September arrives in Kolari, Finland, the UV Index shows a moderate level of 3, indicating a slight shift from the higher summer values of 4 and 5 seen in July and August. This trend marks a transition towards cooler months, where the burn time is reduced to 30 minutes. With the days gradually becoming shorter and the sun's intensity decreasing, it's essential to remain aware of sun exposure during outdoor activities. This is a perfect time to embrace the beauty of the changing seasons while keeping skin protection in mind. For more information on UV trends throughout the year, visit Kolari UV Index.

Maximum UV Index Levels in Kolari for September

The chart shows the monthly maximum UV Index (UVI) for Kolari 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 Kolari typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec112345543111
Data source: Kolari 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 Kolari

In September, Kolari, Finland, basks in the gentle embrace of 252 hours of sunshine, a delightful transition that reflects the waning days of summer. The month embodies a notable dip from August's robust 374 hours, yet it maintains a significant brightness compared to the dimming light of October with only 110 hours. This trend illustrates a gradual shift as the vibrant brightness of the summer months, peaking in June and July with nearly 480 hours, gives way to the crisp, cooler air of autumn. As daylight hours dwindle, the warmth of September serves as a poignant reminder of the vibrant summer just past, while hinting at the long nights ahead.

Monthly Sunshine Duration in Kolari: September Highlighted

The September sunshine duration represents the total number of hours Kolari 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.
JanFebMarAprMayJunJulAugSepOctNovDec23h135h278h354h436h479h477h374h252h110h62h2h
Data source: Kolari September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Kolari During September

In Kolari, Finland, September brings a modest chance of sunny weather with about 26% likelihood for clear skies. This marks a slight dip from the summer months of June and July, both boasting a 44% chance of sunshine, signaling the transition from the bright summer days to the more overcast autumn atmosphere. While September is brighter than January’s dreary 7%, it follows August’s 23%, illustrating the waning days of summer. As the season changes, residents and visitors alike can expect sporadic sunny spells amidst the increasing chill, making every sunlit moment a cherished highlight in the approaching fall.

Percentage of Sunny Days in September in Kolari

The chart illustrates the percentage of sunny days in Kolari 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 Kolari experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec7%28%35%37%20%44%44%24%26%9%22%17%
Data source: Kolari September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Kolari in September

In Kolari, Finland, the transition into September marks a gentle decline in daylight hours, with the region experiencing about 13 hours of sunlight. This follows a vibrant summer where June boasts a remarkable 24 hours of daylight, gradually tapering through July and August. As September unfolds, the lingering brightness starts to shift, leading into the shorter days of autumn. The daylight duration again dwindles as it does each year, signifying the impending shift towards the darker months of October, November, and December, where daylight diminishes to as little as 5 hours. This cyclical pattern highlights the striking contrast in Kolari's daylight throughout the seasons, inviting both tranquility and introspection as nature prepares for winter's embrace.

Average Daylight Hours in Kolari for September

The chart illustrates the variation in daylight duration in Kolari throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 43m7h 55m11h 47m15h 42m20h 20m24h22h 7m17h 3m13h 5m9h 15m5h 11m9h 14m
Data source: Kolari daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Kolari

As September ushers in the transition from summer to autumn in Kolari, Finland, the average wind speed reaches a gentle 3.2 m/s (7 mph). This slight increase from the calmer summer months—reflecting 2.9 m/s in both June and August—hints at the impending chill of autumn. The trending pattern shows winds gradually intensifying, with a notable spike to 3.5 m/s (8 mph) in October, suggesting that the crisp, fresh air associated with fall is on the horizon. This seasonal shift, characterized by slightly brisker winds, invigorates the landscape, inviting residents and visitors alike to embrace the stunning autumn foliage that Kolari has to offer.

Average September Wind Speed in Kolari

The chart displays monthly wind speed patterns in Kolari, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.83.33.63.33.02.93.12.93.2 m/s3.52.73.0
Data source: Kolari September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Kolari Compares to Other Months

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

September and January present starkly contrasting weather conditions. In September, temperatures range from a minimum of -8°C (18°F) to a comfortable maximum of 21°C (71°F), with an average of 7°C (46°F). This month experiences about 67 mm (2.6 in) of precipitation over 11 days, accompanied by high humidity levels of 91%. In contrast, January brings significantly colder temperatures, with a minimum of -34°C (-29°F) and an average of -11°C (12°F), peaking at just 5°C (41°F). Precipitation drops to 36 mm (1.4 in) over 10 days, but humidity levels soar to an unusual 101%. For a closer look at the conditions during this frigid month, check out Kolari weather in January.

September and February present stark contrasts in weather conditions. In September, temperatures range from a minimum of -8°C (18°F) to a pleasant maximum of 21°C (71°F), with an average of 7°C (46°F). The month sees a moderate level of precipitation at 67 mm (2.6 in) spread over about 11 days, while humidity hovers around 91%. Conversely, February is much colder, with temperatures plunging to a minimum of -32°C (-25°F) and an average of -11°C (13°F), peaking at only 7°C (45°F). This month experiences less precipitation at 33 mm (1.3 in) over 8 days, but humidity is notably high at 99%. For a more detailed look at February weather, you can visit Kolari weather in February.

In September, temperatures are relatively mild, ranging from a minimum of -8°C (18°F) to a maximum of 21°C (71°F), with an average of 7°C (46°F). The month experiences around 67 mm (2.6 in) of precipitation over 11 days, and the humidity is high at 91%. In contrast, March is considerably colder, with temperatures dropping to a minimum of -27°C (-17°F) and only reaching a maximum of 9°C (48°F), averaging -6°C (22°F). Precipitation in March is less at 37 mm (1.5 in) over 10 days, and the humidity remains slightly higher at 92%. For more details, you can check Kolari weather in March.

September and April present contrasting weather conditions, despite sharing a maximum temperature of 21°C (71°F). In September, temperatures range from a minimum of -8°C (18°F) to an average of 7°C (46°F), while April experiences lower temperatures with a minimum of -17°C (2°F) and an average of 0°C (32°F). September is wetter, with 67 mm (2.6 in) of precipitation over 11 days, compared to April’s 33 mm (1.3 in) over just 8 days. Humidity levels are slightly higher in September at 91%, contrasted with April's 86%. For more information about the weather in April, check out Kolari weather in April.

In comparing September and May, we see notable differences in temperature and humidity. September typically experiences a mild average temperature of 7°C (46°F), with highs reaching up to 21°C (71°F), while May boasts slightly lower average temperatures at 6°C (44°F) but can peak at a warmer 26°C (78°F). Precipitation in September is higher, totaling 67 mm (2.6 in) over 11 days, compared to May's 49 mm (1.9 in) spread over 10 days. Additionally, humidity levels in September are higher at 91%, whereas May sees a lower but still significant humidity of 82%. This makes September feel wetter and cooler, while May tends to be drier with warmer highs. For more details, check out Kolari weather in May.

In comparing the weather between September and June, there are notable differences in temperature, precipitation, and humidity. September sees cooler temperatures, ranging from a minimum of -8°C (18°F) to a maximum of 21°C (71°F), while June offers a milder range, with minimums at 0°C (32°F) and maximums reaching up to 28°C (83°F). Precipitation levels are similar, with September recording 67 mm (2.6 in) and June slightly higher at 74 mm (2.9 in), both occurring over 11 days. However, September is more humid at 91%, compared to June's 78%, contributing to a more chillier and damp feel as summer transitions to autumn. For a closer look at the climate specifics for that time, you can find information on Kolari weather in June.

In comparing the weather between September and July, August shows a notable difference in temperature and humidity levels. September experiences cooler temperatures with a minimum of -8°C (18°F), an average of 7°C (46°F), and a maximum of 21°C (71°F), while July boasts a much warmer range with temperatures starting at 1°C (35°F), averaging 16°C (61°F), and reaching up to 31°C (89°F). Additionally, September has higher humidity levels at 91%, compared to July's 83%. While both months see a similar number of rainy days, with September recording 11 days of precipitation and July 10 days, the total rainfall in September is slightly lower at 67 mm (2.6 in) compared to July's 81 mm (3.2 in). For a detailed look at the weather during July, you can check Kolari weather in July.

In comparing the weather between September and August, September exhibits cooler temperatures with a minimum of -8°C (18°F) and an average of 7°C (46°F), while August experiences a higher minimum of -1°C (31°F) and an average of 13°C (55°F). The maximum temperatures in September reach 21°C (71°F), significantly lower than August's peak of 30°C (87°F). Additionally, September sees increased precipitation with 67 mm (2.6 in) over 11 days, compared to August's 92 mm (3.6 in) spread across 15 days. Humidity levels are slightly higher in September at 91%, versus 87% in August, contributing to a more damp atmosphere. For more detailed information on August's weather patterns, you can check Kolari weather in August.

September and October present a stark contrast in weather conditions. In September, temperatures range from a minimum of -8°C (18°F) to a pleasant maximum of 21°C (71°F), with an average of 7°C (46°F). The month sees around 67 mm (2.6 in) of precipitation over 11 days, under a relatively high humidity of 91%. In contrast, October experiences significantly colder temperatures, with lows of -22°C (-7°F) and an average of just 1°C (34°F). The maximum temperature reaches only 13°C (55°F). Precipitation increases to 91 mm (3.6 in) over 15 days, accompanied by even higher humidity at 96%. For a detailed look at October's weather in Kolari, check out Kolari weather in October.

In September, temperatures generally range from a minimum of -8°C (18°F) to a maximum of 21°C (71°F), with an average of 7°C (46°F). The month experiences moderate precipitation at 67 mm (2.6 in) over approximately 11 days, with humidity levels around 91%. In contrast, November sees a sharp drop in temperatures, ranging from a minimum of -23°C (-8°F) to a maximum of 7°C (46°F), with an average of -5°C (24°F). Though precipitation is slightly lower at 59 mm (2.3 in), it occurs more frequently on about 13 days, and humidity increases to 98%. These stark differences highlight the transition from early autumn to the frigid grip of late fall. For further details, you can check Kolari weather in November.

In September, temperatures range from a chilly -8°C (18°F) at night to a more comfortable 21°C (71°F) during the day, with an average of 7°C (46°F). The month experiences moderate rainfall, totaling 67 mm (2.6 in) over 11 days, with humidity levels averaging 91%. In contrast, December sees much harsher conditions, with minimum temperatures plunging to -29°C (-20°F) and maximums only reaching 3°C (38°F), resulting in an average temperature of -8°C (17°F). While December has slightly less precipitation at 56 mm (2.2 in) over 14 days, it boasts a higher humidity level of 101%. For a closer look at the December climate specifics, you can visit Kolari weather in December.

Compare Kolari's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Kolari

As September unfolds in Kolari, the transition into autumn becomes unmistakable. The temperatures drop noticeably, offering a refreshing contrast to the warmer months, with average highs only reaching a moderate 21°C (71°F), while brisk lows dip as far as -8°C (18°F). This month also brings a 91% humidity level, making the air feel crisp and alive, yet it’s paired with 67 mm (2.6 in) of precipitation over 11 days, adding a dampness to the vibrant autumn scenery. Given these shifts, September is a time of beautiful transformation, setting the stage for the stunning colors and serene beauty that characterize the change of seasons. For more insights into what to expect, visit Kolari Climate.