September Weather in Saint Stephen, United States

Last updated: June 24, 2025

In Saint Stephen, United States, the average temperature in September hovers around 17°C (62°F). Expect a range that can dip to a chilly 0°C (32°F) or soar to a warm 31°C (89°F). During this month, precipitation amounts to 115 mm (4.5 in) over approximately 9 days, while the air carries an average humidity level of 81%.

September Temperature in Saint Stephen

In September in Saint Stephen, the average temperature is 17°C (62°F). Maximums can reach 31°C (89°F) and minimums can be as low as 0°C (32°F). This makes it a versatile time for traveling, allowing for both warm days and cooler nights, so be sure to pack accordingly!

September Weather in Saint Stephen: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Saint Stephen, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint Stephen, September typically has an average temperature of 17°C (62°F), with highs reaching up to 31°C (89°F) and lows dropping to around 0°C (32°F).

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

September Precipitation in Saint Stephen

In Saint Stephen in September, the precipitation amount is 115 mm (4.5 in) over the course of 9 days, indicating a relatively wet period for the region.

September Precipitation Trends in Saint Stephen

The chart displays monthly precipitation patterns in Saint Stephen, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Saint Stephen, September typically receives around 115 mm (4.5 inches) of precipitation spread over approximately 9 days.

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

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Millimeters (mm) Inches (in)

September Humidity in Saint Stephen

In Saint Stephen in September, humidity is 81%. With an average temperature of 17°C (62°F), this humidity feels like a warm blanket enveloping you, making outdoor adventures feel sticky and requiring frequent breaks to stay comfortable while exploring.

September Average Humidity in Saint Stephen

This chart illustrates the average monthly humidity levels in Saint Stephen, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Saint Stephen is approximately 81%, offering insight into how humid the weather typically is during this month.

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

September UV Index in Saint Stephen

In Saint Stephen in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Saint Stephen.

Maximum UV Index Levels in Saint Stephen for September

The chart shows the monthly maximum UV Index (UVI) for Saint Stephen in September, 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 September, the maximum UV index in Saint Stephen typically reaches 7, which falls under the high exposure category.

Data source: Saint Stephen September 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 September Weather in Saint Stephen Compares to Other Months

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

This table compares monthly weather conditions in Saint Stephen, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-10°C (14°F)	19 mm (0.7 inches)	87%	low
February Weather	-10°C (14°F)	23 mm (0.9 inches)	90%	moderate
March Weather	-1°C (31°F)	46 mm (1.8 inches)	85%	moderate
April Weather	5°C (41°F)	78 mm (3.1 inches)	84%	high
May Weather	14°C (57°F)	86 mm (3.4 inches)	78%	very high
June Weather	21°C (70°F)	72 mm (2.8 inches)	80%	very high
July Weather	23°C (73°F)	105 mm (4.1 inches)	81%	very high
August Weather	21°C (69°F)	139 mm (5.5 inches)	81%	very high
September Weather	17°C (62°F)	115 mm (4.5 inches)	81%	high
October Weather	8°C (46°F)	104 mm (4.1 inches)	84%	moderate
November Weather	-1°C (31°F)	30 mm (1.2 inches)	88%	moderate
December Weather	-6°C (21°F)	46 mm (1.8 inches)	84%	low