January Weather in Greencastle, Ireland

Last updated: August 23, 2025

In January, the average temperature in Greencastle, Ireland hovers around 7°C (44°F). You'll experience a chillier minimum of 1°C (35°F), while the days can warm up to a comfortable maximum of 13°C (55°F). Prepare for some rainy days, as 106 mm (4.2 in) of precipitation typically falls over 17 days, and don't forget: the average humidity is a damp 87%.

January Temperature in Greencastle

In January in Greencastle, the average temperature is 7°C (44°F), with maximums reaching 13°C (55°F) and minimums dipping as low as 1°C (35°F). It's a great time to explore Greencastle, but be sure to pack layers to stay comfortable in the fluctuating temperatures.

January Weather in Greencastle: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Greencastle, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Greencastle, January typically has an average temperature of 7°C (44°F), with highs reaching up to 13°C (55°F) and lows dropping to around 1°C (35°F).

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

January Precipitation in Greencastle

In Greencastle in January, the precipitation amount is 106 mm (4.2 in) spread over 17 days.

January Precipitation Trends in Greencastle

The chart displays monthly precipitation patterns in Greencastle, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Greencastle, January typically receives around 106 mm (4.2 inches) of precipitation spread over approximately 17 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in Greencastle

In Greencastle in January, humidity is 87%. With an average temperature of 7°C (44°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities uncomfortable and requiring travelers to layer up to stay warm and dry.

January Average Humidity in Greencastle

This chart illustrates the average monthly humidity levels in Greencastle, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Greencastle is approximately 87%, offering insight into how humid the weather typically is during this month.

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

January UV Index in Greencastle

In Greencastle in January, 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 Greencastle.

Maximum UV Index Levels in Greencastle for January

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

Data source: Greencastle January 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 January Weather in Greencastle Compares to Other Months

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

This table compares monthly weather conditions in Greencastle, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	7°C (44°F)	106 mm (4.2 inches)	87%	low
February Weather	6°C (44°F)	135 mm (5.3 inches)	86%	low
March Weather	7°C (44°F)	123 mm (4.8 inches)	86%	moderate
April Weather	8°C (47°F)	61 mm (2.4 inches)	85%	moderate
May Weather	10°C (51°F)	79 mm (3.1 inches)	82%	high
June Weather	12°C (54°F)	114 mm (4.5 inches)	84%	very high
July Weather	14°C (57°F)	118 mm (4.7 inches)	86%	very high
August Weather	14°C (58°F)	165 mm (6.5 inches)	86%	high
September Weather	13°C (56°F)	125 mm (4.9 inches)	88%	moderate
October Weather	11°C (53°F)	169 mm (6.6 inches)	89%	moderate
November Weather	9°C (49°F)	150 mm (5.9 inches)	90%	low
December Weather	8°C (46°F)	163 mm (6.4 inches)	86%	low