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September Weather in Siemien, Poland

Last updated: August 27, 2025

In September, the average temperature in Siemien, Poland hovers around 15°C (59°F). Expect a chill, with minimums dipping to 1°C (35°F), while the highs can reach a warm 30°C (86°F). Be prepared for some wet days, as 75 mm (3.0 in) of precipitation is expected over 12 days, alongside an average humidity of 70%.

September Temperature in Siemien

In September in Siemien, the average temperature is 15°C (59°F). Maximum temperatures can reach as high as 30°C (86°F), while minimum temperatures can dip down to 1°C (35°F). This range makes Siemien an ideal destination for travelers seeking a mix of mild weather and the opportunity for outdoor activities.

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

The chart illustrates September temperature patterns in Siemien, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Siemien, September typically has an average temperature of 15°C (59°F), with highs reaching up to 30°C (86°F) and lows dropping to around 1°C (35°F).
JanFebMarAprMayJunJulAugSepOctNovDec303238485768686758504134
Data source: Temperature data for Siemien 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 Siemien

In Siemien in September, the precipitation amount is 75 mm (3.0 in) over the course of 12 days.

September Precipitation Trends in Siemien

The chart displays monthly precipitation patterns in Siemien, 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 Siemien, September typically receives around 75 mm (3.0 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec4043394773778410175633552
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Siemien

In Siemien in September, humidity is 70%. With an average temperature of 15°C (59°F), this humidity feels like a warm embrace, making it slightly uncomfortable while traveling, as the moist air clings to your skin and can leave you feeling slightly lethargic.

September Average Humidity in Siemien

This chart illustrates the average monthly humidity levels in Siemien, 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 Siemien is approximately 70%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec92%90%88%77%62%61%61%60%70%86%90%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Siemien

In Siemien in September, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Siemien, you can refer to this Hourly UV Index in Siemien.

Maximum UV Index Levels in Siemien for September

The chart shows the monthly maximum UV Index (UVI) for Siemien 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 Siemien typically reaches 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec124578876321
Data source: Siemien 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 Siemien Compares to Other Months

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

This table compares monthly weather conditions in Siemien, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-1°C (30°F)40 mm (1.6 inches)92%low
February Weather0°C (32°F)43 mm (1.7 inches)89%low
March Weather3°C (38°F)39 mm (1.5 inches)87%moderate
April Weather9°C (48°F)47 mm (1.8 inches)77%moderate
May Weather14°C (57°F)73 mm (2.9 inches)62%high
June Weather20°C (68°F)77 mm (3.0 inches)61%very high
July Weather20°C (68°F)84 mm (3.3 inches)60%very high
August Weather20°C (68°F)101 mm (4.0 inches)60%high
September Weather15°C (59°F)75 mm (3.0 inches)70%high
October Weather10°C (50°F)63 mm (2.5 inches)86%moderate
November Weather5°C (41°F)35 mm (1.4 inches)90%low
December Weather1°C (34°F)52 mm (2.0 inches)92%low

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