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September Weather in Ilirska Bistrica, Slovenia

Last updated: August 27, 2025

In September, the average temperature in Ilirska Bistrica, Slovenia hovers around 16°C (62°F), offering a mild climate perfect for outdoor activities. Temperatures can vary widely, with minimums dipping to 4°C (39°F) and maximums reaching up to 29°C (85°F). Visitors should be prepared for 12 rainy days, accumulating about 219 mm (8.6 in) of precipitation, while the average humidity sits comfortably at 64%.

September Temperature in Ilirska Bistrica

In September in Ilirska Bistrica, the average temperature is 16°C (62°F). Maximums can reach 29°C (85°F), and minimums can drop as low as 4°C (39°F). This mild climate makes Ilirska Bistrica an ideal destination for travelers seeking comfortable weather for outdoor activities.

September Weather in Ilirska Bistrica: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Ilirska Bistrica, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Ilirska Bistrica, September typically has an average temperature of 16°C (62°F), with highs reaching up to 29°C (85°F) and lows dropping to around 4°C (39°F).
JanFebMarAprMayJunJulAugSepOctNovDec343943505868707061534537
Data source: Temperature data for Ilirska Bistrica 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 Ilirska Bistrica

In Ilirska Bistrica in September, the precipitation amount is 219 mm (8.6 in) over a span of 12 days.

September Precipitation Trends in Ilirska Bistrica

The chart displays monthly precipitation patterns in Ilirska Bistrica, 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 Ilirska Bistrica, September typically receives around 219 mm (8.6 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec91175128136214110117120219170217205
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Ilirska Bistrica

In Ilirska Bistrica in September humidity is 64%. With an average temperature of 16°C (62°F), this humidity feels like a moderate blanket wrapping around you, making it pleasant for traveling but potentially a bit damp as you explore the sights.

September Average Humidity in Ilirska Bistrica

This chart illustrates the average monthly humidity levels in Ilirska Bistrica, 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 Ilirska Bistrica is approximately 64%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%82%73%73%70%69%63%51%64%83%89%88%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Ilirska Bistrica

In Ilirska Bistrica in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Ilirska Bistrica.

Maximum UV Index Levels in Ilirska Bistrica for September

The chart shows the monthly maximum UV Index (UVI) for Ilirska Bistrica 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 Ilirska Bistrica typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235789987532
Data source: Ilirska Bistrica 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 Ilirska Bistrica Compares to Other Months

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

This table compares monthly weather conditions in Ilirska Bistrica, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (34°F)91 mm (3.6 inches)88%low
February Weather4°C (39°F)175 mm (6.9 inches)82%moderate
March Weather6°C (43°F)128 mm (5.0 inches)73%moderate
April Weather10°C (51°F)136 mm (5.4 inches)73%high
May Weather14°C (58°F)214 mm (8.4 inches)70%very high
June Weather20°C (68°F)110 mm (4.3 inches)69%very high
July Weather21°C (70°F)117 mm (4.6 inches)63%very high
August Weather21°C (71°F)120 mm (4.7 inches)51%very high
September Weather16°C (62°F)219 mm (8.6 inches)64%high
October Weather12°C (53°F)170 mm (6.7 inches)83%moderate
November Weather7°C (45°F)217 mm (8.5 inches)89%moderate
December Weather3°C (38°F)205 mm (8.1 inches)88%low

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