September Weather in Duncan, United States

Last updated: June 24, 2025

In September, the average temperature in Duncan, United States hovers around 25°C (77°F), providing a pleasant climate for outdoor activities. Temperatures can dip as low as 11°C (52°F) at night, while daytime highs can soar to 38°C (101°F). With an average precipitation of 29 mm (1.1 in) spread across 4 days, you can expect occasional showers, complemented by an average humidity of 66%. Prepare for a delightful mix of warmth and refreshing rain during your stay!

September Temperature in Duncan

In September in Duncan, the average temperature is 25°C (77°F). Maximum temperatures can reach 38°C (101°F), while minimums can drop as low as 11°C (52°F). Overall, it’s a great time to visit Duncan for those who enjoy warm weather and mild evenings.

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

The chart illustrates September temperature patterns in Duncan, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Duncan, September typically has an average temperature of 25°C (77°F), with highs reaching up to 38°C (101°F) and lows dropping to around 11°C (52°F).

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

September Precipitation in Duncan

In Duncan in September, the precipitation amount is 29 mm (1.1 in) over a span of 4 days.

September Precipitation Trends in Duncan

The chart displays monthly precipitation patterns in Duncan, 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 Duncan, September typically receives around 29 mm (1.1 inches) of precipitation spread over approximately 4 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 Duncan

In Duncan in September humidity is 66%. With an average temperature of 25°C (77°F), this humidity feels like a warm embrace, making travel a pleasant experience as the air is saturated but still breathable, allowing for comfortable exploration.

September Average Humidity in Duncan

This chart illustrates the average monthly humidity levels in Duncan, 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 Duncan is approximately 66%, 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 Duncan

In Duncan in September, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Duncan.

Maximum UV Index Levels in Duncan for September

The chart shows the monthly maximum UV Index (UVI) for Duncan 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 Duncan typically reaches 11, which falls under the extreme exposure category.

Data source: Duncan 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 Duncan Compares to Other Months

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

This table compares monthly weather conditions in Duncan, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	7°C (45°F)	26 mm (1.0 inches)	81%	moderate
February Weather	9°C (48°F)	34 mm (1.3 inches)	82%	high
March Weather	14°C (57°F)	18 mm (0.7 inches)	68%	very high
April Weather	19°C (67°F)	3 mm (0.1 inches)	55%	extreme
May Weather	23°C (74°F)	3 mm (0.1 inches)	45%	extreme
June Weather	29°C (84°F)	6 mm (0.2 inches)	37%	extreme
July Weather	29°C (84°F)	50 mm (2.0 inches)	43%	extreme
August Weather	28°C (83°F)	23 mm (0.9 inches)	53%	extreme
September Weather	25°C (77°F)	29 mm (1.1 inches)	66%	extreme
October Weather	19°C (66°F)	15 mm (0.6 inches)	72%	very high
November Weather	13°C (56°F)	25 mm (1.0 inches)	81%	high
December Weather	8°C (46°F)	25 mm (1.0 inches)	84%	moderate