September weather forecast
Slidell, LA

Share

Weather in September

September in Slidell, Louisiana, comes with a slight relief from high temperatures. The average high temperature drops to 87.3°F (30.7°C), indicating the descent into fall. Though the temperature starts to cool down, humidity remains high at 75%. With 12.3 hours of daylight that transition into beautifully crisp evenings, September remains a pleasant month. September is also unique as it showcases a balanced climate condition, with sufficient sun and decreasing yet notable rainfall.

Temperature

The arrival of September sees a recorded average high-temperature of a still tropical 87.3°F (30.7°C), showing little divergence from the previous month's conditions. Slidell throughout September, experiences an average nighttime temperature of 73.4°F (23°C).

Heat index

September's heat index is evaluated at a very hot 100.4°F (38°C). Emphasize additional safety, risk of heat cramps and heat exhaustion is high. Continuous activity might result in heatstroke.
Metrics for the heat index primarily focus on shaded spots and light wind conditions. Direct exposure to sunlight could raise the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. Physical activity, clothing, and metabolic variations are additional factors that impact an individual's perception of temperature. One should be aware that direct sunshine can amplify the perceived temperature, raising the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Children regularly disregard the necessity to rest and replenish fluids. Thirst is a late symptom of dehydration - thus, maintaining hydration, particularly during long-lasting physical activities, is essential.
The body's self-cooling mechanism is rooted in perspiration, where evaporating sweat cools down excessive warmth. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. If heat absorption exceeds the body's cooling ability, body temperature can elevate, resulting in potential thermal illnesses.

Humidity

The average relative humidity in September is 75%.

Rainfall

In Slidell, in September, during 18.4 rainfall days, 2.4" (61mm) of precipitation is typically accumulated. In Slidell, during the entire year, the rain falls for 173.3 days and collects up to 30.79" (782mm) of precipitation.

Snowfall

In Slidell, 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 the month, sunrise is at 6:36 am and sunset at 7:21 pm. On the last day of September, sunrise is at 6:52 am and sunset at 6:45 pm CDT.

Sunshine

The average sunshine in September is 10.3h.

UV index

In September, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for average individuals.
Note: In September, the UV index of 6 transforms into the following advice:
Escape overexposure. People with light skin may incur burns in fewer than 20 minutes. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.

Frequently asked questions

How hot does it get in September?

Slidell in September has an average high-temperature of 87.3°F (30.7°C) and an average low-temperature of 73.4°F (23°C). The average heat index (a.k.a. 'real feel', 'apparent temperature'), which combines air temperature and relative humidity, in September is evaluated at 100.4°F (38°C).

What is the average humidity in September?

In September, the average relative humidity in Slidell is 75%.

How much does it rain in September?

In Slidell, in September, during 18.4 rainfall days, 2.4" (61mm) of precipitation is typically accumulated.

When it does not snow?

February through December are months without snowfall.

What is the average length of the day in September?

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

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:36 am and sunset at 7:21 pm. On the last day of the month, sunrise is at 6:52 am and sunset at 6:45 pm CDT.

How long on average sun shines in September in Slidell?

The average sunshine duration in September is 10.3h.

How high is the UV index in September?

The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health risk 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
Slidell, LA

Average temperature in September - Slidell, LA
  • Average high temperature in September: 87.3°F

The warmest month (with the highest average high temperature) is July (90.9°F).
The month with the lowest average high temperature is January (59.4°F).

  • Average low temperature in September: 73.4°F

The month with the highest average low temperature is August (77.4°F).
The coldest month (with the lowest average low temperature) is January (45.1°F).

Average pressure in September
Slidell, LA

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

The month with the highest atmospheric pressure is January (30.17"Hg).
The months with the lowest atmospheric pressure are June and August (29.97"Hg).

Average wind speed in September
Slidell, LA

Average wind speed in September - Slidell, LA
  • Average wind speed in September: 5.7mph

The windiest month (with the highest average wind speed) is April (8mph).
The calmest month (with the lowest average wind speed) is July (5.4mph).

Average humidity in September
Slidell, LA

Average humidity in September - Slidell, LA
  • Average humidity in September: 75%

The month with the highest relative humidity is December (79%).
The month with the lowest relative humidity is October (70%).

Average rainfall in September
Slidell, LA

Average rainfall in September - Slidell, LA
  • Average rainfall in September: 2.4"

The wettest month (with the highest rainfall) is August (4.92").
The driest month (with the least rainfall) is November (1.5").

Average rainfall days in September
Slidell, LA

Average rainfall days in September - Slidell, LA
  • Average rainfall days in September: 18.4 days

The month with the highest number of rainy days is August (23.5 days).
The month with the least rainy days is November (8 days).

Average snowfall in September
Slidell, LA

Average snowfall in September - Slidell, LA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (0.2").
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
Slidell, LA

Average snowfall days in September - Slidell, LA
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is January (0.3 days).
The months with the least snowfall days are February, March, April, May, June, July, August, October and November (0 days).

Average daylight in September /
Average sunshine in September
Slidell, LA

Average daylight in September / Average sunshine in September - Slidell, LA
  • 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: 10h and 2min

The month with the most sunshine is June (Average sunshine: 11h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).

Average sunshine days in September
Slidell, LA

Average sunshine days in September - Slidell, LA
  • Average sunshine days in September: 8.1 days

The month with the most sunshine days is November (20.4 days).
The month with the least sunshine days is August (5.1 days).

Average UV index in September
Slidell, LA

Average UV index in September - Slidell, LA
  • 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 December (UV index 3).

Average cloud cover in September
Slidell, LA

Average cloud cover in September - Slidell, LA
  • Average cloud cover in September: 25

The month with the most cloud cover is December (Cloud cover 45).
The month with the least cloud cover is October (Cloud cover 24).

Average visibility in September
Slidell, LA

Average visibility in September - Slidell, 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).

Slidell, Louisiana, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location