September Weather in Monmouth, United States

Last updated: June 24, 2025

In September, the average temperature in Monmouth, United States is a pleasant 21°C (69°F). Expect a minimum chill of 6°C (43°F) and a maximum heat reaching up to 35°C (94°F). With an average humidity of 78%, it's advisable to stay hydrated, especially during the 8 days of the month's total 99 mm (3.9 in) of precipitation. Enjoy the varied weather while exploring the beauty of Monmouth!

September Temperature in Monmouth

In September in Monmouth, the average temperature is 21°C (69°F). Maximums can reach 35°C (94°F), while minimums can drop as low as 6°C (43°F). This makes it an ideal time to explore the outdoors and enjoy various activities in Monmouth.

September Weather in Monmouth: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Monmouth, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Monmouth, September typically has an average temperature of 21°C (69°F), with highs reaching up to 35°C (94°F) and lows dropping to around 6°C (43°F).

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

September Precipitation in Monmouth

In Monmouth in September, the precipitation amount is 99 mm (3.9 in) spread over 8 days.

September Precipitation Trends in Monmouth

The chart displays monthly precipitation patterns in Monmouth, 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 Monmouth, September typically receives around 99 mm (3.9 inches) of precipitation spread over approximately 8 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Monmouth

In Monmouth in September, humidity is 78%. With an average temperature of 21°C (69°F), this humidity feels like a warm embrace that clings to your skin, making outdoor activities feel more intense and leaving you yearning for refreshing breezes or a cool drink as you explore.

September Average Humidity in Monmouth

This chart illustrates the average monthly humidity levels in Monmouth, 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 Monmouth is approximately 78%, 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 Monmouth

In Monmouth in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Monmouth.

Maximum UV Index Levels in Monmouth for September

The chart shows the monthly maximum UV Index (UVI) for Monmouth 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 Monmouth typically reaches 8, which falls under the very high exposure category.

Data source: Monmouth 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 Monmouth Compares to Other Months

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

This table compares monthly weather conditions in Monmouth, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (26°F)	56 mm (2.2 inches)	81%	moderate
February Weather	-2°C (28°F)	63 mm (2.5 inches)	81%	moderate
March Weather	5°C (41°F)	102 mm (4.0 inches)	81%	high
April Weather	10°C (51°F)	99 mm (3.9 inches)	82%	very high
May Weather	17°C (64°F)	166 mm (6.6 inches)	78%	very high
June Weather	23°C (75°F)	138 mm (5.4 inches)	81%	extreme
July Weather	25°C (78°F)	93 mm (3.7 inches)	79%	very high
August Weather	23°C (75°F)	64 mm (2.5 inches)	77%	very high
September Weather	21°C (69°F)	99 mm (3.9 inches)	78%	very high
October Weather	13°C (55°F)	126 mm (5.0 inches)	78%	high
November Weather	4°C (40°F)	51 mm (2.0 inches)	87%	moderate
December Weather	1°C (33°F)	49 mm (1.9 inches)	84%	low