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September Weather in Ilomantsi, Finland

Last updated: August 23, 2025

In September, the average temperature in Ilomantsi, Finland hovers around 9°C (49°F), with a minimum dip of -3°C (27°F) and a delightful maximum of 23°C (74°F). Expect about 78 mm (3.1 in) of precipitation spread over 14 days, contributing to an average humidity of a crisp 91%. Stay prepared for a mix of chilly days and the occasional warmer spell!

September Temperature in Ilomantsi

In September in Ilomantsi, the average temperature is 9°C (49°F), with maximums reaching 23°C (74°F) and minimums dropping as low as -3°C (27°F). It's advisable to pack layers and prepare for varying weather conditions during your travels.

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

The chart illustrates September temperature patterns in Ilomantsi, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Ilomantsi, September typically has an average temperature of 9°C (49°F), with highs reaching up to 23°C (74°F) and lows dropping to around -3°C (27°F).
JanFebMarAprMayJunJulAugSepOctNovDec181825354759625849393123
Data source: Temperature data for Ilomantsi 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 Ilomantsi

In Ilomantsi in September, the precipitation amount is 78 mm (3.1 in) over a period of 14 days.

September Precipitation Trends in Ilomantsi

The chart displays monthly precipitation patterns in Ilomantsi, 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 Ilomantsi, September typically receives around 78 mm (3.1 inches) of precipitation spread over approximately 14 days.
JanFebMarAprMayJunJulAugSepOctNovDec4950544661609510578856171
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Ilomantsi

In Ilomantsi 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 Ilomantsi

This chart illustrates the average monthly humidity levels in Ilomantsi, 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 Ilomantsi is approximately 91%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec99%98%95%88%79%76%83%89%92%95%95%97%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Ilomantsi

In Ilomantsi 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 Ilomantsi, you can check the information here.

Maximum UV Index Levels in Ilomantsi for September

The chart shows the monthly maximum UV Index (UVI) for Ilomantsi 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 Ilomantsi typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec113456653211
Data source: Ilomantsi 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 Ilomantsi Compares to Other Months

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

This table compares monthly weather conditions in Ilomantsi, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-8°C (19°F)49 mm (1.9 inches)99%low
February Weather-8°C (18°F)50 mm (2.0 inches)98%low
March Weather-4°C (25°F)54 mm (2.1 inches)95%moderate
April Weather1°C (35°F)46 mm (1.8 inches)88%moderate
May Weather9°C (48°F)60 mm (2.4 inches)79%moderate
June Weather15°C (60°F)60 mm (2.3 inches)76%high
July Weather17°C (62°F)95 mm (3.7 inches)83%high
August Weather15°C (59°F)105 mm (4.1 inches)89%moderate
September Weather9°C (49°F)78 mm (3.1 inches)91%moderate
October Weather4°C (40°F)85 mm (3.4 inches)95%low
November Weather0°C (31°F)61 mm (2.4 inches)95%low
December Weather-5°C (24°F)71 mm (2.8 inches)97%low

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