September weather forecast
Gretna, LA

September beckons the start of more clement weather in Gretna with a decrease in temperatures. Decreased rainfall of 0.47" (12mm) signals drier days. Average sunlight hours start to decline, thus signaling the advent of autumn. The slight increase in wind speed results in cooler nights, preparing residents for the upcoming change in month and weather. However, with a consistent UV index of 7, outdoor activities still remain a joy.

Temperature

September in Gretna observes an average high-temperature of a still hot 86.5°F (30.3°C), marking an insignificant difference from August's 89.4°F (31.9°C). Gretna experiences an average temperature drop to a warm 76.3°F (24.6°C) during September nights.

Heat index

Throughout September, the heat index is estimated at a sweltering 98.6°F (37°C). More protective measures are required - heat exhaustion and heat cramps are likely. Heatstroke may follow lengthy activity.
Bear in mind that the heat index values are determined for shaded areas and light breezes. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. A person's impression of weather can be swayed by numerous aspects, among them metabolic variations, pregnancy, and activity levels. Direct exposure to the sun's rays can enhance the felt temperature, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Children frequently do not comprehend the need for rest and hydration. Thirst is an advanced stage of dehydration - staying hydrated, especially during extended physical exercises, is essential.
The body's inherent cooling system operates through perspiration, wherein evaporating sweat offsets excessive heat. With a high level of moisture in the air, the evaporation process becomes less efficient, preventing the body from cooling down efficiently and resulting in a sensation of overheating. When body temperature rises due to excess heat gain beyond its removal capability, one might experience heat-related disorders.

Humidity

The average relative humidity in September in Gretna is 73%.

Rainfall

In September, in Gretna, Louisiana, the rain falls for 11.7 days. Throughout September, 0.47" (12mm) of precipitation is accumulated. Throughout the year, in Gretna, there are 112.1 rainfall days, and 9.37" (238mm) of precipitation is accumulated.

Snowfall

February through December are months without snowfall.

Daylight

In September, the average length of the day is 12h and 20min.
On the first day of September, sunrise is at 6:37 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:53 am and sunset at 6:46 pm CDT.

Sunshine

In Gretna, the average sunshine in September is 10.1h.

UV index

May through September, with an average maximum UV index of 7, are months with the highest UV index in Gretna. A UV Index of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: In September, a regular UV index of 7 translates into these guidelines:
Act on precautions and pay attention to sun safety recommendations. Avoidance of sunburn is obligatory. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is at its strongest, and remember that parasols or canopies do not offer full protection. To cut down UV radiation exposure by about half, sport a wide-brim hat.