September Weather in Sumy, Ukraine

Last updated: August 28, 2025

In Sumy, Ukraine, the average temperature in September hovers around 15°C (60°F). Be prepared for fluctuations, as temperatures can dip to a chilly -1°C (31°F) and soar up to a warm 33°C (92°F). Precipitation is moderate, with about 39 mm (1.5 in) spread over 8 days. Expect an average humidity level of 69%, making it a unique time to experience this destination!

September Temperature in Sumy

In September in Sumy, the average temperature is 15°C (60°F), with maximums potentially reaching 33°C (92°F) and minimums dropping as low as -1°C (31°F). This diverse temperature range makes Sumy an interesting destination for travelers seeking both warmth and a chance to experience cooler conditions.

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

The chart illustrates September temperature patterns in Sumy, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sumy, September typically has an average temperature of 15°C (60°F), with highs reaching up to 33°C (92°F) and lows dropping to around -1°C (31°F).

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

September Precipitation in Sumy

In Sumy in September, the precipitation amount is 39 mm (1.5 in) over the course of 8 days.

September Precipitation Trends in Sumy

The chart displays monthly precipitation patterns in Sumy, 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 Sumy, September typically receives around 39 mm (1.5 inches) of precipitation spread over approximately 8 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 Sumy

In Sumy in September, humidity is 69%. With an average temperature of 15°C (60°F), this humidity feels like a cool, damp embrace that can make outdoor activities feel slightly heavier and more exhausting, but still inviting for exploring the charming sights and sounds of the area.

September Average Humidity in Sumy

This chart illustrates the average monthly humidity levels in Sumy, 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 Sumy is approximately 69%, 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 Sumy

In Sumy 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 Sumy, you can refer to this Hourly UV Index in Sumy.

Maximum UV Index Levels in Sumy for September

The chart shows the monthly maximum UV Index (UVI) for Sumy 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 Sumy typically reaches 6, which falls under the high exposure category.

Data source: Sumy 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 Sumy Compares to Other Months

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

This table compares monthly weather conditions in Sumy, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (25°F)	43 mm (1.7 inches)	92%	low
February Weather	-3°C (26°F)	45 mm (1.8 inches)	93%	low
March Weather	1°C (35°F)	40 mm (1.6 inches)	90%	moderate
April Weather	9°C (48°F)	40 mm (1.6 inches)	79%	moderate
May Weather	15°C (59°F)	64 mm (2.5 inches)	66%	high
June Weather	20°C (68°F)	58 mm (2.3 inches)	65%	very high
July Weather	21°C (69°F)	84 mm (3.3 inches)	55%	very high
August Weather	21°C (69°F)	28 mm (1.1 inches)	49%	high
September Weather	15°C (60°F)	39 mm (1.5 inches)	69%	high
October Weather	9°C (49°F)	36 mm (1.4 inches)	84%	moderate
November Weather	2°C (36°F)	37 mm (1.4 inches)	92%	low
December Weather	-1°C (30°F)	69 mm (2.7 inches)	94%	low