March Weather in Saint John, United States

Last updated: June 24, 2025

In March, the average temperature in Saint John, United States hovers around 4°C (39°F). However, brace yourself for extremes, as temperatures can plummet to a minimum of -18°C (0°F) and soar to a maximum of 25°C (76°F). This month also brings 99 mm (3.9 in) of precipitation spread over about 13 days, contributing to a high average humidity of 84%. Prepare for a mix of crisp and wet conditions!

March Temperature in Saint John

In March in Saint John, the average temperature is 4°C (39°F), with maximums reaching up to 25°C (76°F) and minimums dropping as low as -18°C (0°F). Be sure to pack layers to stay comfortable during your travels!

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

The chart illustrates March 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, March typically has an average temperature of 4°C (39°F), with highs reaching up to 25°C (76°F) and lows dropping to around -18°C (0°F).

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

March Precipitation in Saint John

In Saint John in March, the precipitation amount is 99 mm (3.9 in) over the course of 13 days.

March Precipitation Trends in Saint John

The chart displays monthly precipitation patterns in Saint John, with values for each month alongside March’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how March’s conditions compare to those of other months. In Saint John, March typically receives around 99 mm (3.9 inches) of precipitation spread over approximately 13 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

March Humidity in Saint John

In Saint John in March, humidity is 84%. With an average temperature of 4°C (39°F), this humidity feels like a damp chill that seeps into your bones, making outdoor excursions uncomfortable and demanding more layers than you anticipate while traveling.

March Average Humidity in Saint John

This chart illustrates the average monthly humidity levels in Saint John, with March’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In March, average humidity in Saint John is approximately 84%, offering insight into how humid the weather typically is during this month.

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

March UV Index in Saint John

In Saint John in March, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Saint John, you can refer to this Hourly UV Index in Saint John.

Maximum UV Index Levels in Saint John for March

The chart shows the monthly maximum UV Index (UVI) for Saint John in March, 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 March, the maximum UV index in Saint John typically reaches 6, which falls under the high exposure category.

Data source: Saint John March 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 March 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 March’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 March’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-3°C (27°F)	70 mm (2.7 inches)	82%	moderate
February Weather	-2°C (29°F)	71 mm (2.8 inches)	83%	moderate
March Weather	4°C (39°F)	99 mm (3.9 inches)	84%	high
April Weather	9°C (48°F)	119 mm (4.7 inches)	85%	very high
May Weather	16°C (60°F)	162 mm (6.4 inches)	79%	very high
June Weather	22°C (71°F)	130 mm (5.1 inches)	82%	very high
July Weather	24°C (75°F)	103 mm (4.1 inches)	80%	very high
August Weather	23°C (73°F)	92 mm (3.6 inches)	81%	very high
September Weather	20°C (68°F)	74 mm (2.9 inches)	80%	very high
October Weather	13°C (56°F)	142 mm (5.6 inches)	82%	high
November Weather	5°C (40°F)	68 mm (2.7 inches)	88%	moderate
December Weather	1°C (34°F)	60 mm (2.4 inches)	84%	low