January Weather in Castletown, United Kingdom

Last updated: August 27, 2025

In January, the average temperature in Castletown, United Kingdom hovers around 5°C (42°F). Expect chilly days with minimums dropping to -6°C (22°F) and highs reaching up to 14°C (57°F). With an average precipitation of 57 mm (2.2 in) spread across 11 days, you may want to carry an umbrella. Don't forget, the average humidity is quite high at 82%, making the air feel cooler and more refreshing!

January Temperature in Castletown

In January in Castletown, the average temperature is 5°C (42°F), with maximums reaching 14°C (57°F) and minimums dropping as low as -6°C (22°F). It's advisable to pack layers and prepare for chilly conditions during your travels.

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

The chart illustrates January temperature patterns in Castletown, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Castletown, January typically has an average temperature of 5°C (42°F), with highs reaching up to 14°C (57°F) and lows dropping to around -6°C (22°F).

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

January Precipitation in Castletown

In Castletown in January, the precipitation amount is 57 mm (2.2 in) spread over 11 days.

January Precipitation Trends in Castletown

The chart displays monthly precipitation patterns in Castletown, 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 Castletown, January typically receives around 57 mm (2.2 inches) of precipitation spread over approximately 11 days.

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

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Millimeters (mm) Inches (in)

January Humidity in Castletown

In Castletown in January humidity is 82%. With an average temperature of 5°C (42°F), this humidity feels like a wet chill that seeps into your bones, making outdoor exploration uncomfortable and dampening the joy of traveling.

January Average Humidity in Castletown

This chart illustrates the average monthly humidity levels in Castletown, 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 Castletown is approximately 82%, 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 Castletown

In Castletown 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 Castletown.

Maximum UV Index Levels in Castletown for January

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

Data source: Castletown 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 Castletown Compares to Other Months

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

This table compares monthly weather conditions in Castletown, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	5°C (42°F)	57 mm (2.2 inches)	82%	low
February Weather	5°C (42°F)	62 mm (2.5 inches)	81%	low
March Weather	6°C (43°F)	72 mm (2.8 inches)	81%	moderate
April Weather	7°C (45°F)	55 mm (2.2 inches)	81%	moderate
May Weather	10°C (50°F)	67 mm (2.6 inches)	83%	moderate
June Weather	13°C (55°F)	70 mm (2.8 inches)	84%	high
July Weather	14°C (58°F)	74 mm (2.9 inches)	87%	high
August Weather	14°C (58°F)	79 mm (3.1 inches)	86%	high
September Weather	13°C (55°F)	109 mm (4.3 inches)	88%	moderate
October Weather	10°C (51°F)	112 mm (4.4 inches)	87%	moderate
November Weather	8°C (46°F)	92 mm (3.6 inches)	87%	low
December Weather	6°C (43°F)	71 mm (2.8 inches)	80%	low