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September Weather in Mikkeli, Finland

Last updated: August 23, 2025

In September, the average temperature in Mikkeli, Finland hovers around 11°C (51°F). Expect chilly days with minimum temperatures dipping to -1°C (31°F), while highs can reach up to 22°C (72°F). On average, 71 mm (2.8 in) of precipitation falls over 12 days, and the humidity is a notable 90%, keeping the atmosphere quite moist.

September Temperature in Mikkeli

In September in Mikkeli, the average temperature is 11°C (51°F). Maximums can reach 22°C (72°F), while minimums can drop as low as -1°C (31°F). This range makes it essential to pack layers for your travels, ensuring you're prepared for both warm days and chilly evenings.

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

The chart illustrates September temperature patterns in Mikkeli, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Mikkeli, September typically has an average temperature of 11°C (51°F), with highs reaching up to 22°C (72°F) and lows dropping to around -1°C (31°F).
JanFebMarAprMayJunJulAugSepOctNovDec232128364861636051423426
Data source: Temperature data for Mikkeli 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 Mikkeli

In Mikkeli in September, the precipitation amount is 71 mm (2.8 in) during a total of 12 days.

September Precipitation Trends in Mikkeli

The chart displays monthly precipitation patterns in Mikkeli, 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 Mikkeli, September typically receives around 71 mm (2.8 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec494544445366818671765870
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Mikkeli

In Mikkeli in September, humidity is 90%. With an average temperature of 11°C (51°F), this humidity feels like a damp blanket wrapping around you, making traveling uncomfortable and sticky, as every step leaves you feeling sluggish and clinging to the air.

September Average Humidity in Mikkeli

This chart illustrates the average monthly humidity levels in Mikkeli, 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 Mikkeli is approximately 90%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec98%96%93%87%75%74%80%85%90%94%94%96%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Mikkeli

In Mikkeli 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 Mikkeli, you can check the information here.

Maximum UV Index Levels in Mikkeli for September

The chart shows the monthly maximum UV Index (UVI) for Mikkeli 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 Mikkeli typically reaches 3, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec113456753211
Data source: Mikkeli 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 Mikkeli Compares to Other Months

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

This table compares monthly weather conditions in Mikkeli, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-5°C (23°F)49 mm (1.9 inches)98%low
February Weather-6°C (22°F)45 mm (1.8 inches)96%low
March Weather-2°C (28°F)44 mm (1.7 inches)93%moderate
April Weather2°C (36°F)44 mm (1.7 inches)87%moderate
May Weather9°C (49°F)53 mm (2.1 inches)75%moderate
June Weather16°C (61°F)66 mm (2.6 inches)74%high
July Weather17°C (64°F)81 mm (3.2 inches)80%high
August Weather16°C (60°F)86 mm (3.4 inches)85%moderate
September Weather11°C (51°F)71 mm (2.8 inches)90%moderate
October Weather6°C (42°F)76 mm (3.0 inches)94%low
November Weather1°C (35°F)58 mm (2.3 inches)94%low
December Weather-3°C (27°F)70 mm (2.8 inches)96%low

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