December Weather in Sejny, Poland

Last updated: August 27, 2025

In December, the average temperature in Sejny, Poland hovers around 0°C (32°F), with fluctuations ranging from a brisk -14°C (8°F) to a mild 10°C (50°F). Expect 53 mm (2.1 in) of precipitation over approximately 13 days, contributing to a high average humidity of 93%.

December Temperature in Sejny

In December in Sejny, the average temperature is 0°C (32°F), with maximums reaching up to 10°C (50°F) and minimums dropping as low as -14°C (8°F). Travelers should be prepared for a chilly climate, with a significant chance of cold weather during their visit.

December Weather in Sejny: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Sejny, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sejny, December typically has an average temperature of 0°C (32°F), with highs reaching up to 10°C (50°F) and lows dropping to around -14°C (8°F).

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

December Precipitation in Sejny

In Sejny in December, the precipitation amount is 53 mm (2.1 in) over the course of 13 days.

December Precipitation Trends in Sejny

The chart displays monthly precipitation patterns in Sejny, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Sejny, December typically receives around 53 mm (2.1 inches) of precipitation spread over approximately 13 days.

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

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Millimeters (mm) Inches (in)

December Humidity in Sejny

In Sejny in December, humidity is 93%. With an average temperature of 0°C (32°F), this humidity feels like a bone-chilling cold that seeps into your clothes, making every step outside feel damp and uncomfortable for traveling.

December Average Humidity in Sejny

This chart illustrates the average monthly humidity levels in Sejny, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Sejny is approximately 93%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Sejny

In Sejny in December, the maximum UV index is 1, which corresponds to a low Exposure Category. This means you have a time to burn of 45 minutes. For more details, you can check the Hourly UV Index in Sejny.

Maximum UV Index Levels in Sejny for December

The chart shows the monthly maximum UV Index (UVI) for Sejny in December, 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 December, the maximum UV index in Sejny typically reaches 1, which falls under the low exposure category.

Data source: Sejny December 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 December Weather in Sejny Compares to Other Months

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

This table compares monthly weather conditions in Sejny, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-2°C (29°F)	41 mm (1.6 inches)	93%	low
February Weather	-1°C (30°F)	34 mm (1.3 inches)	90%	low
March Weather	2°C (36°F)	40 mm (1.6 inches)	88%	moderate
April Weather	7°C (45°F)	45 mm (1.8 inches)	77%	moderate
May Weather	13°C (55°F)	70 mm (2.8 inches)	59%	high
June Weather	18°C (65°F)	51 mm (2.0 inches)	59%	very high
July Weather	19°C (66°F)	93 mm (3.7 inches)	60%	high
August Weather	18°C (65°F)	87 mm (3.4 inches)	60%	high
September Weather	14°C (57°F)	70 mm (2.7 inches)	72%	moderate
October Weather	9°C (48°F)	61 mm (2.4 inches)	88%	moderate
November Weather	4°C (40°F)	39 mm (1.5 inches)	91%	low
December Weather	0°C (32°F)	53 mm (2.1 inches)	93%	low