September Weather in Marietta, United States

Last updated: June 24, 2025

In September, the average temperature in Marietta, United States hovers around 25°C (77°F). Expect minimums of 9°C (49°F) and delightful highs reaching up to 36°C (97°F). With an average humidity of 65% and 102 mm (4.0 in) of precipitation spread over 7 days, this month offers a mix of warmth and a touch of moisture, perfect for exploring the vibrant surroundings!

September Temperature in Marietta

In September in Marietta, the average temperature is 25°C (77°F). Maximums can reach 36°C (97°F), while minimums can dip as low as 9°C (49°F). It's advisable to pack for warm days and cooler nights when traveling during this time.

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

The chart illustrates September temperature patterns in Marietta, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Marietta, September typically has an average temperature of 25°C (77°F), with highs reaching up to 36°C (97°F) and lows dropping to around 9°C (49°F).

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

September Precipitation in Marietta

In Marietta in September, the total precipitation amount is 102 mm (4.0 in) over a period of 7 days.

September Precipitation Trends in Marietta

The chart displays monthly precipitation patterns in Marietta, 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 Marietta, September typically receives around 102 mm (4.0 inches) of precipitation spread over approximately 7 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 Marietta

In Marietta in September, humidity is 65%. With an average temperature of 25°C (77°F), this humidity feels like a warm embrace, making outdoor activities slightly uncomfortable but still bearable, as the sticky air clings to your skin and encourages you to seek shade or a refreshing drink.

September Average Humidity in Marietta

This chart illustrates the average monthly humidity levels in Marietta, 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 Marietta is approximately 65%, 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 Marietta

In Marietta in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Marietta.

Maximum UV Index Levels in Marietta for September

The chart shows the monthly maximum UV Index (UVI) for Marietta 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 Marietta typically reaches 10, which falls under the very high exposure category.

Data source: Marietta 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 Marietta Compares to Other Months

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

This table compares monthly weather conditions in Marietta, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	6°C (44°F)	61 mm (2.4 inches)	80%	moderate
February Weather	8°C (46°F)	84 mm (3.3 inches)	79%	high
March Weather	14°C (58°F)	95 mm (3.7 inches)	78%	very high
April Weather	17°C (63°F)	96 mm (3.8 inches)	78%	very high
May Weather	22°C (73°F)	122 mm (4.8 inches)	81%	extreme
June Weather	27°C (80°F)	103 mm (4.1 inches)	78%	extreme
July Weather	29°C (84°F)	48 mm (1.9 inches)	73%	extreme
August Weather	28°C (83°F)	94 mm (3.7 inches)	66%	extreme
September Weather	25°C (77°F)	102 mm (4.0 inches)	65%	very high
October Weather	18°C (65°F)	138 mm (5.4 inches)	72%	very high
November Weather	12°C (54°F)	50 mm (2.0 inches)	82%	high
December Weather	9°C (49°F)	57 mm (2.2 inches)	87%	moderate