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September Weather in Mount Pleasant, United States

Last updated: June 24, 2025

In Mount Pleasant, United States, the average temperature in September hovers around 18°C (64°F), making it a pleasant time to visit. However, don’t be surprised by the extremes; temperatures can dip to a chilly 0°C (33°F) or soar to a scorching 35°C (95°F). Expect about 104 mm (4.1 in) of precipitation spread over 10 days, with an average humidity level of around 80%, creating a wonderfully lush atmosphere.

September Temperature in Mount Pleasant

In September in Mount Pleasant, the average temperature is 18°C (64°F). Maximum temperatures can reach 35°C (95°F), while minimums can drop as low as 0°C (33°F). Dress in layers to enjoy the varied climate and take advantage of outdoor activities throughout the day.

September Weather in Mount Pleasant: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Mount Pleasant, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Mount Pleasant, September typically has an average temperature of 18°C (64°F), with highs reaching up to 35°C (95°F) and lows dropping to around 0°C (33°F).
JanFebMarAprMayJunJulAugSepOctNovDec242535455868747164523730
Data source: Temperature data for Mount Pleasant 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 Mount Pleasant

In Mount Pleasant in September, the precipitation amount is 104 mm (4.1 in) over a period of 10 days.

September Precipitation Trends in Mount Pleasant

The chart displays monthly precipitation patterns in Mount Pleasant, 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 Mount Pleasant, September typically receives around 104 mm (4.1 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec5558588911611265801041225665
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Mount Pleasant

In Mount Pleasant in September humidity is 80%. With an average temperature of 18°C (64°F), this humidity feels like a warm, damp blanket wrapping around you, making travel a bit more exhausting as the air thickens and the heat clings to your skin.

September Average Humidity in Mount Pleasant

This chart illustrates the average monthly humidity levels in Mount Pleasant, 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 Mount Pleasant is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%87%85%86%80%80%80%81%80%84%90%86%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Mount Pleasant

In Mount Pleasant 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 Mount Pleasant.

Maximum UV Index Levels in Mount Pleasant for September

The chart shows the monthly maximum UV Index (UVI) for Mount Pleasant 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 Mount Pleasant typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec2458910997532
Data source: Mount Pleasant 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 Mount Pleasant Compares to Other Months

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

This table compares monthly weather conditions in Mount Pleasant, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-4°C (24°F)55 mm (2.2 inches)88%low
February Weather-4°C (25°F)58 mm (2.3 inches)87%moderate
March Weather2°C (35°F)58 mm (2.3 inches)85%moderate
April Weather7°C (45°F)89 mm (3.5 inches)86%very high
May Weather15°C (58°F)116 mm (4.6 inches)80%very high
June Weather20°C (69°F)112 mm (4.4 inches)80%very high
July Weather23°C (74°F)65 mm (2.5 inches)80%very high
August Weather22°C (71°F)80 mm (3.1 inches)80%very high
September Weather18°C (64°F)104 mm (4.1 inches)80%high
October Weather11°C (52°F)122 mm (4.8 inches)84%moderate
November Weather3°C (38°F)56 mm (2.2 inches)89%moderate
December Weather-1°C (31°F)65 mm (2.6 inches)86%low

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