September Weather in Iisalmi, Finland

Last updated: August 23, 2025

In September, the average temperature in Iisalmi, Finland hovers around 9°C (49°F). Expect a temperature range where the minimum dips to -4°C (25°F) and the maximum can soar to 23°C (75°F). Be prepared for some moisture, as the area receives an average precipitation of 85 mm (3.4 in) over 14 days, all while boasting a high average humidity of 91%.

September Temperature in Iisalmi

In September in Iisalmi, the average temperature is 9°C (49°F). Maximums can reach 23°C (75°F) and minimums can be as low as -4°C (25°F). It's a great time for travelers to experience mild weather, but they should be prepared for temperature fluctuations.

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

The chart illustrates September temperature patterns in Iisalmi, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Iisalmi, September typically has an average temperature of 9°C (49°F), with highs reaching up to 23°C (75°F) and lows dropping to around -4°C (25°F).

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

September Precipitation in Iisalmi

In Iisalmi in September, the precipitation amount is 85 mm (3.4 in) spread over 14 days, contributing to the region's overall climate patterns.

September Precipitation Trends in Iisalmi

The chart displays monthly precipitation patterns in Iisalmi, 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 Iisalmi, September typically receives around 85 mm (3.4 inches) of precipitation spread over approximately 14 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 Iisalmi

In Iisalmi in September humidity is 91%. With an average temperature of 9°C (49°F), this humidity feels like a chilly mist enveloping you, making travel uncomfortable as the dampness seeps into your clothing and chills you to the bone.

September Average Humidity in Iisalmi

This chart illustrates the average monthly humidity levels in Iisalmi, 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 Iisalmi is approximately 91%, 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 Iisalmi

In Iisalmi in September, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Iisalmi, you can check the information here.

Maximum UV Index Levels in Iisalmi for September

The chart shows the monthly maximum UV Index (UVI) for Iisalmi 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 Iisalmi typically reaches 3, which falls under the moderate exposure category.

Data source: Iisalmi 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 Iisalmi Compares to Other Months

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

This table compares monthly weather conditions in Iisalmi, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-7°C (20°F)	48 mm (1.9 inches)	99%	low
February Weather	-8°C (18°F)	44 mm (1.7 inches)	97%	low
March Weather	-4°C (26°F)	44 mm (1.7 inches)	95%	low
April Weather	2°C (35°F)	46 mm (1.8 inches)	87%	moderate
May Weather	8°C (47°F)	56 mm (2.2 inches)	78%	moderate
June Weather	15°C (59°F)	70 mm (2.8 inches)	74%	high
July Weather	17°C (63°F)	88 mm (3.5 inches)	80%	high
August Weather	15°C (58°F)	101 mm (4.0 inches)	85%	moderate
September Weather	9°C (49°F)	85 mm (3.4 inches)	91%	moderate
October Weather	4°C (40°F)	88 mm (3.5 inches)	95%	low
November Weather	0°C (32°F)	77 mm (3.0 inches)	94%	low
December Weather	-4°C (24°F)	65 mm (2.6 inches)	98%	low