January Weather in Saint John, United States

Last updated: June 24, 2025

In January, the average temperature in Saint John, United States hovers around 1°C (35°F), with a minimum dipping as low as -18°C (1°F) and a maximum reaching 13°C (55°F). Expect 62 mm (2.5 in) of precipitation spread across 12 days, contributing to a high average humidity of 85%. Stay warm and prepared for wet days ahead!

January Temperature in Saint John

In January in Saint John, the average temperature is 1°C (35°F). Maximum temperatures can reach 13°C (55°F), while minimums can drop to as low as -18°C (1°F). Be sure to pack warm clothing if you're planning to travel during this month!

January Weather in Saint John: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Saint John, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint John, January typically has an average temperature of 1°C (35°F), with highs reaching up to 13°C (55°F) and lows dropping to around -18°C (1°F).

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

January Precipitation in Saint John

In Saint John in January, the precipitation amount is 62 mm (2.5 in) over the course of 12 days.

January Precipitation Trends in Saint John

The chart displays monthly precipitation patterns in Saint John, 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 Saint John, January typically receives around 62 mm (2.5 inches) of precipitation spread over approximately 12 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 Saint John

In Saint John in January humidity is 85%. With an average temperature of 1°C (35°F), this humidity feels like a chilly blanket wrapping around you, making outdoor adventures damp and uncomfortable, especially for travelers unprepared for such a heavy and cold atmosphere.

January Average Humidity in Saint John

This chart illustrates the average monthly humidity levels in Saint John, 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 Saint John is approximately 85%, 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 Saint John

In Saint John in January, the maximum UV index is 2, which corresponds to a low exposure category. With this level of UV radiation, the time to burn is approximately 45 minutes. To learn more about the hourly UV index in Saint John, you can visit Hourly UV Index in Saint John.

Maximum UV Index Levels in Saint John for January

The chart shows the monthly maximum UV Index (UVI) for Saint John 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 Saint John typically reaches 2, which falls under the low exposure category.

Data source: Saint John 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 Saint John Compares to Other Months

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

This table compares monthly weather conditions in Saint John, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	1°C (35°F)	62 mm (2.5 inches)	85%	low
February Weather	1°C (34°F)	74 mm (2.9 inches)	86%	moderate
March Weather	6°C (42°F)	56 mm (2.2 inches)	86%	moderate
April Weather	10°C (50°F)	48 mm (1.9 inches)	82%	high
May Weather	15°C (59°F)	45 mm (1.8 inches)	77%	very high
June Weather	20°C (68°F)	20 mm (0.8 inches)	79%	very high
July Weather	24°C (76°F)	2 mm (0.1 inches)	77%	very high
August Weather	24°C (75°F)	10 mm (0.4 inches)	62%	very high
September Weather	18°C (64°F)	22 mm (0.9 inches)	60%	high
October Weather	10°C (50°F)	54 mm (2.1 inches)	80%	moderate
November Weather	5°C (41°F)	74 mm (2.9 inches)	87%	moderate
December Weather	1°C (34°F)	70 mm (2.8 inches)	86%	low