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September Weather in Duncan, United States

Last updated: June 24, 2025

In September, the average temperature in Duncan, United States hovers around 23°C (74°F). You can expect a minimum of 8°C (46°F) and a maximum that can reach up to 35°C (95°F). With 144 mm (5.7 in) of precipitation spread over 9 days, the average humidity sits at a comfortable 75%, making the climate quite engaging for visitors and locals alike.

September Temperature in Duncan

In September in Duncan, the average temperature is 23°C (74°F). Maximums can reach 35°C (95°F), while minimums can drop as low as 8°C (46°F). This makes Duncan an ideal destination for travelers seeking a pleasant and varied climate.

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 23°C (74°F), with highs reaching up to 35°C (95°F) and lows dropping to around 8°C (46°F).
JanFebMarAprMayJunJulAugSepOctNovDec434853617075797873645046
Data source: Temperature data for Duncan generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Duncan

In Duncan in September, the precipitation amount is 144 mm (5.7 in) spread over 9 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 144 mm (5.7 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec98136101126128778210914413393130
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Duncan

In Duncan in September, humidity is 75%. With an average temperature of 23°C (74°F), this humidity feels like a warm, heavy blanket wrapping around you, making it feel more sweltering than it actually is, which can be quite uncomfortable for traveling.

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 75%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec86%85%84%82%83%82%80%74%75%79%87%87%
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 is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, 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 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec47810111111109864
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.
 TemperaturePrecipitationHumidityUV
January Weather6°C (43°F)98 mm (3.9 inches)86%moderate
February Weather9°C (48°F)136 mm (5.4 inches)85%high
March Weather12°C (53°F)100 mm (4.0 inches)84%very high
April Weather16°C (61°F)126 mm (5.0 inches)82%very high
May Weather21°C (70°F)128 mm (5.0 inches)83%extreme
June Weather24°C (76°F)77 mm (3.0 inches)82%extreme
July Weather26°C (80°F)82 mm (3.2 inches)80%extreme
August Weather25°C (78°F)109 mm (4.3 inches)74%very high
September Weather23°C (74°F)144 mm (5.7 inches)75%very high
October Weather18°C (64°F)133 mm (5.2 inches)79%very high
November Weather10°C (50°F)93 mm (3.6 inches)87%high
December Weather8°C (46°F)130 mm (5.1 inches)87%moderate

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