September weather forecast
Gretna, FL

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Weather in September

September, the first month of the autumn in Gretna, is still a hot month, with an average temperature fluctuating between 69.4°F (20.8°C) and 87.3°F (30.7°C).

Temperature

As September unfolds, the average high-temperature reaches a still tropical 87.3°F (30.7°C), hinting at a slight fluctuation from the previous month. In the month of September, the average low-temperature usually rests at an agreeable 69.4°F (20.8°C).

Heat index

During September, the heat index is computed to be a torrid 102.2°F (39°C). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.
Evaluating the heat index requires understanding its values in the shade and with gentle winds. Direct exposure to sunshine could lead to a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', melds the effects of warmth and moisture to generate a feeling of heat. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Young children are more at risk than adults since they tend to sweat less. Moreover, their large skin surface in proportion to their small bodies and the high heat production due to their activities contribute to their vulnerability.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. When there is abundant moisture in the air, the body's cooling through the evaporation process becomes less effective, leading to the sensation of overheating. Heat-related complications, like dehydration, can manifest if the body's heat gain exceeds its dissipation capacity.

Humidity

In Gretna, the average relative humidity in September is 77%.

Rainfall

In September, the rain falls for 19.4 days. Throughout September, 3.35" (85mm) of precipitation is accumulated. In Gretna, during the entire year, the rain falls for 184.9 days and collects up to 37.6" (955mm) of precipitation.

Snowfall

In Gretna, snow does not fall in February through December.

Daylight

In September, the average length of the day is 12h and 20min.
On the first day of September, sunrise is at 7:15 am and sunset at 8:01 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 7:24 pm EDT.

Sunshine

In Gretna, the average sunshine in September is 8.6h.

UV index

In Gretna, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for ordinary individuals.
Note: An average UV index of 6 in September transforms into this advice:
Persist with precautions and heed sun safety advice. Prevention of sunburn is compulsory. To the best of your ability, limit your exposure to the sun between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is it hot in Gretna during September?

In September, the average high-temperature and low-temperature are 87.3°F (30.7°C) and 69.4°F (20.8°C) respectively. The average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines relative humidity and air temperature, in September is computed to be 102.2°F (39°C).

What is the average humidity in September in Gretna?

The average relative humidity in September is 77%.

How much does it rain in Gretna in September?

In Gretna, during September, the rain falls for 19.4 days and regularly aggregates up to 3.35" (85mm) of precipitation.

When it does not snow in Gretna?

February through December are months without snowfall in Gretna, Florida.

How many hours of daylight does Gretna have in September?

The average day length in September is 12h and 20min.

What time are sunrise and sunset in September in Gretna?

In September, on the first day of the month, sunrise is at 7:15 am and sunset at 8:01 pm. On the last day of the month, in Gretna, sunrise is at 7:31 am and sunset at 7:24 pm EDT.

How long on average sun shines in September in Gretna?

In September, the average sunshine duration in Gretna is 8.6h.

How high is the UV index in September in Gretna?

In September, the average daily maximum UV index in Gretna, Florida, is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from unprotected exposure to 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, FL

Average temperature in September - Gretna, FL
  • Average high temperature in September: 87.3°F

The warmest months (with the highest average high temperature) are July and August (90.7°F).
The month with the lowest average high temperature is January (60.4°F).

  • Average low temperature in September: 69.4°F

The month with the highest average low temperature is August (73.6°F).
The coldest month (with the lowest average low temperature) is January (42.3°F).

Average pressure in September
Gretna, FL

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

The month with the highest atmospheric pressure is January (30.16"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.98"Hg).

Average wind speed in September
Gretna, FL

Average wind speed in September - Gretna, FL
  • Average wind speed in September: 4.9mph

The windiest months (with the highest average wind speed) are January and March (6.6mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).

Average humidity in September
Gretna, FL

Average humidity in September - Gretna, FL
  • Average humidity in September: 77%

The months with the highest relative humidity are August and December (78%).
The month with the lowest relative humidity is May (72%).

Average rainfall in September
Gretna, FL

Average rainfall in September - Gretna, FL
  • Average rainfall in September: 3.35"

The wettest month (with the highest rainfall) is August (5.08").
The driest month (with the least rainfall) is November (1.46").

Average rainfall days in September
Gretna, FL

Average rainfall days in September - Gretna, FL
  • Average rainfall days in September: 19.4 days

The month with the highest number of rainy days is July (26.1 days).
The month with the least rainy days is November (8.1 days).

Average snowfall in September
Gretna, FL

Average snowfall in September - Gretna, FL
  • Average snowfall in September: 0"

The month with the highest snowfall is January (0.04").
The months with the least snowfall are February, March, April, May, June, July, August, September, October, November and December (0").

Average snowfall days in September
Gretna, FL

Average snowfall days in September - Gretna, FL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (0.2 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).

Average daylight in September /
Average sunshine in September
Gretna, FL

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

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

  • Average sunshine in September: 8h and 4min

The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).

Average sunshine days in September
Gretna, FL

Average sunshine days in September - Gretna, FL
  • Average sunshine days in September: 9.3 days

The month with the most sunshine days is November (20.6 days).
The month with the least sunshine days is July (3.4 days).

Average UV index in September
Gretna, FL

Average UV index in September - Gretna, FL
  • Average UV index in September: 6

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

Average cloud cover in September
Gretna, FL

Average cloud cover in September - Gretna, FL
  • Average cloud cover in September: 32

The month with the most cloud cover is December (Cloud cover 43).
The months with the least cloud cover are May and October (Cloud cover 29).

Average visibility in September
Gretna, FL

Average visibility in September - Gretna, FL
  • Average visibility in September: 5mi

The months with the highest visibility are January, February, March, April, May, June, October and November (6mi).
The months with the lowest visibility are July, August, September and December (5mi).

Gretna, Florida, USA

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