January Weather in St Johnston, Ireland

Last updated: August 23, 2025

In January, the average temperature in St Johnston, Ireland hovers around 5°C (42°F). Expect a chilly minimum of -4°C (25°F) and a mild maximum of 14°C (57°F). During this month, precipitation typically accumulates to 72 mm (2.8 in) over the course of 13 days, and the air maintains a damp average humidity of 84%. Prepare for a cool, wet season!

January Temperature in St Johnston

In January in St Johnston, the average temperature is 5°C (42°F). Maximum temperatures can reach 14°C (57°F), while minimum temperatures can drop as low as -4°C (25°F). Be prepared for chilly weather and bring warm clothing if you're planning to travel during this time.

January Weather in St Johnston: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in St Johnston, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In St Johnston, 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 -4°C (25°F).

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

January Precipitation in St Johnston

In St Johnston in January, the precipitation amount is 72 mm (2.8 in) over a period of 13 days.

January Precipitation Trends in St Johnston

The chart displays monthly precipitation patterns in St Johnston, 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 St Johnston, January typically receives around 72 mm (2.8 inches) of precipitation spread over approximately 13 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 St Johnston

In St Johnston in January, humidity is 84%. With an average temperature of 5°C (42°F), this humidity feels like a thick blanket wrapping around you, making every step feel heavier while traveling.

January Average Humidity in St Johnston

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

In St Johnston 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 St Johnston.

Maximum UV Index Levels in St Johnston for January

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

Data source: St Johnston 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 St Johnston Compares to Other Months

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

This table compares monthly weather conditions in St Johnston, 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)	72 mm (2.8 inches)	84%	low
February Weather	6°C (42°F)	113 mm (4.4 inches)	84%	low
March Weather	6°C (44°F)	106 mm (4.2 inches)	83%	moderate
April Weather	8°C (47°F)	64 mm (2.5 inches)	84%	moderate
May Weather	11°C (52°F)	93 mm (3.7 inches)	83%	high
June Weather	13°C (56°F)	107 mm (4.2 inches)	83%	very high
July Weather	15°C (59°F)	99 mm (3.9 inches)	86%	very high
August Weather	15°C (58°F)	157 mm (6.2 inches)	86%	high
September Weather	13°C (55°F)	97 mm (3.8 inches)	87%	moderate
October Weather	10°C (50°F)	112 mm (4.4 inches)	87%	moderate
November Weather	7°C (46°F)	94 mm (3.7 inches)	88%	low
December Weather	6°C (43°F)	103 mm (4.1 inches)	84%	low