December Weather in Port Saint John, United States

Last updated: June 24, 2025

In December, the average temperature in Port Saint John, United States hovers around 19°C (66°F), making it a pleasant time to visit. Expect a range from a cool 6°C (42°F) to a warm 27°C (80°F). Be prepared for some rain, as total precipitation amounts to 65 mm (2.6 in) over approximately 8 days. With an average humidity of 84%, it's a perfect opportunity to enjoy the local scenery while staying refreshed!

December Temperature in Port Saint John

In December in Port Saint John, the average temperature is 19°C (66°F). The maximum can reach 27°C (80°F), and the minimum can be as low as 6°C (42°F). This climate makes Port Saint John an ideal destination for travelers looking to enjoy mild and pleasant weather.

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

The chart illustrates December temperature patterns in Port 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 Port Saint John, December typically has an average temperature of 19°C (66°F), with highs reaching up to 27°C (80°F) and lows dropping to around 6°C (42°F).

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

December Precipitation in Port Saint John

In Port Saint John in December, the total precipitation amount is 65 mm (2.6 in) spread over the course of 8 days.

December Precipitation Trends in Port Saint John

The chart displays monthly precipitation patterns in Port Saint John, 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 Port Saint John, December typically receives around 65 mm (2.6 inches) of precipitation spread over approximately 8 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

December Humidity in Port Saint John

In Port Saint John in December, humidity is 84%. With an average temperature of 19°C (66°F), this humidity feels like a warm, sticky embrace that can make traveling uncomfortable and exhausting, as the air clings to your skin, and every step taken feels heavier in the sultry atmosphere.

December Average Humidity in Port Saint John

This chart illustrates the average monthly humidity levels in Port Saint John, 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 Port Saint John 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 Port Saint John

In Port Saint John in December, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Port Saint John.

Maximum UV Index Levels in Port Saint John for December

The chart shows the monthly maximum UV Index (UVI) for Port Saint John 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 Port Saint John typically reaches 5, which falls under the moderate exposure category.

Data source: Port Saint John 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 Port Saint John Compares to Other Months

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

This table compares monthly weather conditions in Port Saint John, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	17°C (64°F)	38 mm (1.5 inches)	83%	high
February Weather	19°C (67°F)	51 mm (2.0 inches)	80%	very high
March Weather	20°C (69°F)	25 mm (1.0 inches)	75%	very high
April Weather	23°C (73°F)	72 mm (2.8 inches)	70%	extreme
May Weather	25°C (77°F)	124 mm (4.9 inches)	68%	extreme
June Weather	26°C (80°F)	164 mm (6.4 inches)	75%	extreme
July Weather	27°C (82°F)	172 mm (6.8 inches)	79%	extreme
August Weather	28°C (82°F)	220 mm (8.7 inches)	81%	extreme
September Weather	27°C (81°F)	189 mm (7.4 inches)	83%	extreme
October Weather	26°C (78°F)	107 mm (4.2 inches)	81%	very high
November Weather	22°C (71°F)	62 mm (2.4 inches)	82%	high
December Weather	19°C (66°F)	65 mm (2.6 inches)	84%	moderate