September weather forecast
Gretna Green, LA

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Weather in September

The first month of the autumn, September, is also a hot month in Gretna Green, Louisiana, with an average temperature fluctuating between 87.8°F (31°C) and 68°F (20°C).

Temperature

September's advent presents an average high-temperature of a still tropical 87.8°F (31°C), indicating a slight variation from the conditions of the previous month. Throughout September nights, Gretna Green registers an average low-temperature of 68°F (20°C).

Heat index

September's heat index is calculated to be a fiery hot 102.2°F (39°C). Incorporate additional safety actions, heat cramps and heat exhaustion are possible. Long-term activity may induce heatstroke.
Heat index readings emphasize conditions of light breezes and shaded spots. Heat index values have the potential to be boosted by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. The individual's temperature perception can be influenced by numerous factors such as metabolic variations, physical activity, and clothing. Consider the sun's direct rays and their impact; they can potentially increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Kids are usually in more danger than grown-ups as they tend to sweat less. Plus, their bigger skin surface in relation to their small frames and increased heat generation due to their activity level make them more susceptible.
Normally, the human body cools itself through perspiration, which removes excessive heat by evaporating sweat. In conditions of both high temperature and humidity (a high heat index), sweating is limited and the perception of heat is enhanced. Elevated heat gain compared to the body's release capability poses risks of dehydration and potential overheating.

Humidity

In Gretna Green, the average relative humidity in September is 74%.

Rainfall

In Gretna Green, in September, during 12.7 rainfall days, 2.2" (56mm) of precipitation is typically accumulated. Throughout the year, in Gretna Green, there are 154.1 rainfall days, and 35.12" (892mm) of precipitation is accumulated.

Snowfall

In Gretna Green, snow does not fall in April through December.

Daylight

The average length of the day in September is 12h and 21min.
On the first day of the month, sunrise is at 6:41 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:59 am and sunset at 6:51 pm CDT.

Sunshine

In September, the average sunshine is 9.7h.

UV index

In Gretna Green, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the ordinary person.
Note: In September, a regular UV index of 6 translates into these guidelines:
Guard against overexposure. Protection from sun-induced harm is essential. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Updated: Aug 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot does it get in September?

In Gretna Green, 87.8°F (31°C) is the average high-temperature and 68°F (20°C) is the average low-temperature during September. In September, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines relative humidity and air temperature, is calculated to be 102.2°F (39°C).

What is the average humidity in September in Gretna Green?

In September, the average relative humidity is 74%.

How many days does it rain in September?

In Gretna Green, in September, during 12.7 rainfall days, 2.2" (56mm) of precipitation is typically accumulated.

When it does not snow?

In Gretna Green, snow does not fall in April through December.

How many hours of daylight does Gretna Green have in September?

The average day length in September is 12h and 21min.

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:41 am and sunset at 7:29 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:51 pm CDT.

How many hours of sunshine does Gretna Green have in September?

The average sunshine duration in September is 9.7h.

How high is the UV index in September?

The average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Gretna Green, LA

Average temperature in September - Gretna Green, LA
  • Average high temperature in September: 87.8°F

The warmest month (with the highest average high temperature) is July (91.2°F).
The month with the lowest average high temperature is January (55°F).

  • Average low temperature in September: 68°F

The month with the highest average low temperature is August (73°F).
The coldest month (with the lowest average low temperature) is January (40.3°F).

Average pressure in September
Gretna Green, LA

Average pressure in September - Gretna Green, LA
  • Average pressure in September: 29.98"Hg

The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).

Average wind speed in September
Gretna Green, LA

Average wind speed in September - Gretna Green, LA
  • Average wind speed in September: 5.3mph

The windiest month (with the highest average wind speed) is February (8.3mph).
The calmest months (with the lowest average wind speed) are July and September (5.3mph).

Average humidity in September
Gretna Green, LA

Average humidity in September - Gretna Green, LA
  • Average humidity in September: 74%

The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is October (69%).

Average rainfall in September
Gretna Green, LA

Average rainfall in September - Gretna Green, LA
  • Average rainfall in September: 2.2"

The wettest month (with the highest rainfall) is April (3.43").
The driest month (with the least rainfall) is November (2.13").

Average rainfall days in September
Gretna Green, LA

Average rainfall days in September - Gretna Green, LA
  • Average rainfall days in September: 12.7 days

The month with the highest number of rainy days is August (15.5 days).
The month with the least rainy days is October (8.5 days).

Average snowfall in September
Gretna Green, LA

Average snowfall in September - Gretna Green, LA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (0.55").
The months with the least snowfall are April, May, June, July, August, September, October, November and December (0").

Average snowfall days in September
Gretna Green, LA

Average snowfall days in September - Gretna Green, LA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (0.8 days).
The months with the least snowfall days are April, May, June, July, August, September, October, November and December (0 days).

Average daylight in September /
Average sunshine in September
Gretna Green, LA

Average daylight in September / Average sunshine in September - Gretna Green, LA
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 12min).
The month with the shortest days is December (Average daylight: 10h and 6min).

  • Average sunshine in September: 9h and 4min

The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 4h and 48min).

Average sunshine days in September
Gretna Green, LA

Average sunshine days in September - Gretna Green, LA
  • Average sunshine days in September: 16.2 days

The month with the most sunshine days is October (21.4 days).
The month with the least sunshine days is February (13.3 days).

Average UV index in September
Gretna Green, LA

Average UV index in September - Gretna Green, LA
  • Average UV index in September: 6

The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January and December (UV index 3).

Average cloud cover in September
Gretna Green, LA

Average cloud cover in September - Gretna Green, LA
  • Average cloud cover in September: 30

The month with the most cloud cover is February (Cloud cover 48).
The months with the least cloud cover are June and October (Cloud cover 28).

Average visibility in September
Gretna Green, LA

Average visibility in September - Gretna Green, LA
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Gretna Green, Louisiana, USA

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