September Weather in Gretna, United States

Last updated: June 24, 2025

In September, the average temperature in Gretna, United States hovers around 26°C (79°F), with a comfortable minimum of 14°C (57°F) and the occasional peak reaching 37°C (100°F). Expect about 140 mm (5.5 in) of precipitation spread over 13 days, contributing to an average humidity level of 83%—perfect for those who enjoy a lush, tropical atmosphere!

September Temperature in Gretna

In September in Gretna, the average temperature is 26°C (79°F). Maximum temperatures can reach 37°C (100°F), while minimum temperatures can drop as low as 14°C (57°F). It's a great time for travelers to enjoy warm weather while still having cool evenings to relax.

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

The chart illustrates September temperature patterns in Gretna, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Gretna, September typically has an average temperature of 26°C (79°F), with highs reaching up to 37°C (100°F) and lows dropping to around 14°C (57°F).

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

September Precipitation in Gretna

In Gretna in September, the total precipitation amount is 140 mm (5.5 in) over the course of 13 days.

September Precipitation Trends in Gretna

The chart displays monthly precipitation patterns in Gretna, 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 Gretna, September typically receives around 140 mm (5.5 inches) of precipitation spread over approximately 13 days.

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

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Millimeters (mm) Inches (in)

September Humidity in Gretna

In Gretna in September, humidity is 83%. With an average temperature of 26°C (79°F), this humidity feels like a heavy blanket enveloping you, making travel an exercise in endurance as the air clings to your skin and saps your energy.

September Average Humidity in Gretna

This chart illustrates the average monthly humidity levels in Gretna, 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 Gretna is approximately 83%, 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 Gretna

In Gretna 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 Gretna.

Maximum UV Index Levels in Gretna for September

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

Data source: Gretna 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 Gretna Compares to Other Months

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

This table compares monthly weather conditions in Gretna, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	12°C (54°F)	82 mm (3.2 inches)	85%	moderate
February Weather	15°C (60°F)	116 mm (4.6 inches)	82%	very high
March Weather	17°C (63°F)	57 mm (2.2 inches)	80%	very high
April Weather	20°C (68°F)	101 mm (4.0 inches)	76%	very high
May Weather	24°C (76°F)	87 mm (3.4 inches)	73%	extreme
June Weather	26°C (80°F)	176 mm (6.9 inches)	74%	extreme
July Weather	27°C (81°F)	169 mm (6.6 inches)	80%	extreme
August Weather	27°C (81°F)	165 mm (6.5 inches)	79%	extreme
September Weather	26°C (79°F)	140 mm (5.5 inches)	83%	very high
October Weather	23°C (73°F)	99 mm (3.9 inches)	77%	very high
November Weather	16°C (60°F)	46 mm (1.8 inches)	84%	high
December Weather	13°C (56°F)	126 mm (5.0 inches)	88%	moderate