September Weather in Koski Tl, Finland

Last updated: August 23, 2025

In September, the average temperature in Koski Tl, Finland is a cool 11°C (52°F), with daily highs reaching up to 24°C (76°F) and lows dipping to -4°C (25°F). Expect around 62 mm (2.4 in) of precipitation over 12 days, and a high average humidity of 90%, making the atmosphere quite damp.

September Temperature in Koski Tl

In September in Koski Tl, the average temperature is 11°C (52°F). Maximums can reach 24°C (76°F), while minimums can drop as low as -4°C (25°F). It's advisable to pack layered clothing to comfortably adapt to the varying temperatures throughout the day.

September Weather in Koski Tl: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Koski Tl, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Koski Tl, September typically has an average temperature of 11°C (52°F), with highs reaching up to 24°C (76°F) and lows dropping to around -4°C (25°F).

Data source: Temperature data for Koski Tl generated using information from the Copernicus Climate Change Service.

September Precipitation in Koski Tl

In Koski Tl in September, the precipitation amount is 62 mm (2.4 in) spread over 12 days.

September Precipitation Trends in Koski Tl

The chart displays monthly precipitation patterns in Koski Tl, 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 Koski Tl, September typically receives around 62 mm (2.4 inches) of precipitation spread over approximately 12 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

September Humidity in Koski Tl

In Koski Tl in September, humidity is 90%. With an average temperature of 11°C (52°F), this humidity feels like a heavy blanket that clings to your skin, making travel uncomfortable and muggy.

September Average Humidity in Koski Tl

This chart illustrates the average monthly humidity levels in Koski Tl, 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 Koski Tl is approximately 90%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Koski Tl

In Koski Tl in September, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Koski Tl for better planning.

Maximum UV Index Levels in Koski Tl for September

The chart shows the monthly maximum UV Index (UVI) for Koski Tl 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 Koski Tl typically reaches 4, which falls under the moderate exposure category.

Data source: Koski Tl 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.

How September Weather in Koski Tl Compares to Other Months

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

This table compares monthly weather conditions in Koski Tl, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-3°C (27°F)	49 mm (1.9 inches)	97%	low
February Weather	-4°C (25°F)	44 mm (1.7 inches)	95%	low
March Weather	-1°C (30°F)	46 mm (1.8 inches)	93%	moderate
April Weather	4°C (39°F)	41 mm (1.6 inches)	86%	moderate
May Weather	10°C (50°F)	59 mm (2.3 inches)	75%	moderate
June Weather	16°C (62°F)	59 mm (2.3 inches)	75%	high
July Weather	17°C (64°F)	83 mm (3.3 inches)	80%	high
August Weather	16°C (61°F)	88 mm (3.5 inches)	83%	moderate
September Weather	11°C (52°F)	62 mm (2.4 inches)	90%	moderate
October Weather	6°C (43°F)	77 mm (3.0 inches)	93%	low
November Weather	2°C (37°F)	52 mm (2.1 inches)	94%	low
December Weather	-2°C (30°F)	67 mm (2.6 inches)	95%	low