September Weather in Koszalin, Poland

Last updated: August 27, 2025

In Koszalin, Poland, the average temperature in September is a mild 15°C (59°F). However, you can expect a minimum of 5°C (42°F) and a maximum of 31°C (87°F), making for a diverse temperature range. During this time, precipitation averages 81 mm (3.2 in), typically spread over 14 days. Coupled with an average humidity of 81%, the climate can feel quite lush and vibrant.

September Temperature in Koszalin

In September in Koszalin, the average temperature is 15°C (59°F), with a maximum that can reach 31°C (87°F) and a minimum that can drop as low as 5°C (42°F). Be sure to pack layers to accommodate the varying temperatures while exploring this destination!

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

The chart illustrates September temperature patterns in Koszalin, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Koszalin, September typically has an average temperature of 15°C (59°F), with highs reaching up to 31°C (87°F) and lows dropping to around 5°C (42°F).

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

September Precipitation in Koszalin

In Koszalin in September, the precipitation amount is 81 mm (3.2 in) over a span of 14 days.

September Precipitation Trends in Koszalin

The chart displays monthly precipitation patterns in Koszalin, 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 Koszalin, September typically receives around 81 mm (3.2 inches) of precipitation spread over approximately 14 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Koszalin

In Koszalin in September humidity is 81%. With an average temperature of 15°C (59°F), this humidity feels like a heavy blanket draped over you, making traveling quite uncomfortable as you constantly wipe away beads of sweat and feel the stickiness clinging to your clothes.

September Average Humidity in Koszalin

This chart illustrates the average monthly humidity levels in Koszalin, 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 Koszalin is approximately 81%, 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 Koszalin

In Koszalin in September, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Koszalin.

Maximum UV Index Levels in Koszalin for September

The chart shows the monthly maximum UV Index (UVI) for Koszalin 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 Koszalin typically reaches 5, which falls under the moderate exposure category.

Data source: Koszalin 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 Koszalin Compares to Other Months

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

This table compares monthly weather conditions in Koszalin, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	2°C (35°F)	61 mm (2.4 inches)	87%	low
February Weather	2°C (35°F)	50 mm (2.0 inches)	87%	low
March Weather	4°C (39°F)	54 mm (2.1 inches)	87%	moderate
April Weather	7°C (45°F)	35 mm (1.4 inches)	85%	moderate
May Weather	12°C (54°F)	55 mm (2.2 inches)	81%	high
June Weather	18°C (64°F)	51 mm (2.0 inches)	81%	high
July Weather	18°C (65°F)	110 mm (4.3 inches)	81%	high
August Weather	19°C (66°F)	66 mm (2.6 inches)	80%	high
September Weather	15°C (59°F)	81 mm (3.2 inches)	81%	moderate
October Weather	11°C (52°F)	92 mm (3.6 inches)	84%	moderate
November Weather	7°C (44°F)	58 mm (2.3 inches)	86%	low
December Weather	3°C (37°F)	62 mm (2.4 inches)	85%	low