December Weather in Letterkenny, Ireland

Last updated: August 23, 2025

In December, the average temperature in Letterkenny, Ireland is a brisk 6°C (44°F), with lows dipping to -2°C (28°F) and highs reaching up to 13°C (56°F). Expect 124 mm (4.9 in) of precipitation over approximately 20 days, coupled with an average humidity of 84%. Be prepared for a mix of chilly and wet conditions!

December Temperature in Letterkenny

In December in Letterkenny, the average temperature is 6°C (44°F). Maximum temperatures can reach 13°C (56°F), while minimums can drop as low as -2°C (28°F). Make sure to pack warm layers if you're planning to travel during this time.

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

The chart illustrates December temperature patterns in Letterkenny, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Letterkenny, December typically has an average temperature of 6°C (44°F), with highs reaching up to 13°C (56°F) and lows dropping to around -2°C (28°F).

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

December Precipitation in Letterkenny

In Letterkenny, in December, the precipitation amount is 124 mm (4.9 in) over the course of 20 days.

December Precipitation Trends in Letterkenny

The chart displays monthly precipitation patterns in Letterkenny, 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 Letterkenny, December typically receives around 124 mm (4.9 inches) of precipitation spread over approximately 20 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 Letterkenny

In Letterkenny in December humidity is 84%. With an average temperature of 6°C (44°F), this humidity feels like a chilly dampness that clings to your skin, making outdoor activities less comfortable and necessitating layered clothing to stay warm and dry while exploring the area.

December Average Humidity in Letterkenny

This chart illustrates the average monthly humidity levels in Letterkenny, 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 Letterkenny is approximately 84%, 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 Letterkenny

In Letterkenny 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 Letterkenny.

Maximum UV Index Levels in Letterkenny for December

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

Data source: Letterkenny 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 Letterkenny Compares to Other Months

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

This table compares monthly weather conditions in Letterkenny, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	6°C (43°F)	85 mm (3.3 inches)	84%	low
February Weather	6°C (42°F)	123 mm (4.8 inches)	84%	low
March Weather	6°C (44°F)	111 mm (4.4 inches)	83%	moderate
April Weather	8°C (47°F)	59 mm (2.3 inches)	84%	moderate
May Weather	11°C (52°F)	81 mm (3.2 inches)	83%	high
June Weather	13°C (56°F)	102 mm (4.0 inches)	83%	very high
July Weather	15°C (59°F)	98 mm (3.9 inches)	86%	very high
August Weather	14°C (58°F)	146 mm (5.8 inches)	86%	high
September Weather	13°C (55°F)	104 mm (4.1 inches)	87%	moderate
October Weather	10°C (51°F)	124 mm (4.9 inches)	87%	moderate
November Weather	8°C (46°F)	108 mm (4.2 inches)	88%	low
December Weather	6°C (44°F)	124 mm (4.9 inches)	84%	low