September weather forecast
Opelousas, LA

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Weather in September

September signals the onset of autumn in Opelousas, Louisiana, bringing with it a welcome relief from the intense heat of the past summer months. With the high temperature dialing down to a comfortable 86.9°F (30.5°C), locals find it pleasant enough for a range of outdoor activities. A significant drop in rain compared to July and August at 0.75" (19mm) brings drier days, and the air starts to feel crisp as the month progresses. The anticipation of October's even cooler temperatures and delightful autumn foliage makes September a month of seasonal transition and budding excitement in Opelousas.

Temperature

The shift into September in Opelousas records an average high-temperature of a still tropical 86.9°F (30.5°C), subtly varied from August's 90.1°F (32.3°C). September brings with it a nighttime average temperature of 69.6°F (20.9°C).

Heat index

Throughout September, the heat index is computed to be a very hot 102.2°F (39°C). Take extra safety measures to prevent heat exhaustion and heat cramps. Heatstroke could follow lengthy activity.
Heat index details are generally centered around shaded locations and a mild breeze. Direct sunlight exposure may result in a rise of the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', melds the effects of warmth and moisture to generate a feeling of heat. The impact of weather is personal, differing among a variety of people based on differences in body mass, height, and the level of physical exertion. Given direct exposure to sunlight, one might experience a rise in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Typically, children face more danger than adults as they usually perspire less. Their larger skin surface relative to their small bodies and increased heat output from their activities enhance their risk.
The human body has a built-in cooling mechanism through perspiration; evaporating sweat dissipates the excess heat. Excessive relative humidity disturbs the body's typical cooling process by reducing evaporation, leading to a decrease in body cooling rate and an increase in the sensation of warmth. Heat disorders may be on the horizon when body temperatures rise from inadequate heat management.

Humidity

The average relative humidity in September in Opelousas is 80%.

Rainfall

In September, the rain falls for 13.1 days. Throughout September, 0.75" (19mm) of precipitation is accumulated. Throughout the year, there are 127.3 rainfall days, and 11.65" (296mm) of precipitation is accumulated.

Snowfall

February through November are months without snowfall.

Daylight

The average length of the day in September is 12h and 20min.
On the first day of the month, sunrise is at 6:45 am and sunset at 7:30 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:54 pm CDT.

Sunshine

In Opelousas, the average sunshine in September is 9.4h.

UV index

In September, the average daily maximum UV index is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV radiation for the ordinary person.
Note: In September, the maximum UV index of 6 translates into these guidelines:
Exercise precautions and adapt sun safety practices. Defence against skin and eye affliction is paramount. Between 10 a.m. and 4 p.m., UV radiation is strongest. Make an effort to avoid direct sunlight during this time, remembering that shade structures may not provide full sun protection. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.

Frequently asked questions

Is it hot during September?

In Opelousas, 86.9°F (30.5°C) is the average high-temperature and 69.6°F (20.9°C) is the average low-temperature during September. The average heat index (a.k.a. 'real feel', 'felt air temperature'), which combines air temperature and relative humidity, in September is computed to be 102.2°F (39°C).

What is the average humidity in September?

The average relative humidity in September is 80%.

How many days does it rain in September?

In Opelousas, in September, during 13.1 rainfall days, 0.75" (19mm) of precipitation is typically accumulated.

When it does not snow?

February through November are months without snowfall.

How many hours of daylight does Opelousas have in September?

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

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:45 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:54 pm CDT.

How many hours of sunshine does Opelousas have in September?

In Opelousas, the average sunshine duration in September is 9.4h.

What is the UV index reading in September?

The average daily maximum UV index in September 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
Opelousas, LA

Average temperature in September - Opelousas, LA
  • Average high temperature in September: 86.9°F

The warmest month (with the highest average high temperature) is July (90.3°F).
The month with the lowest average high temperature is January (57.7°F).

  • Average low temperature in September: 69.6°F

The month with the highest average low temperature is August (73.8°F).
The coldest month (with the lowest average low temperature) is January (42.4°F).

Average pressure in September
Opelousas, LA

Average pressure in September - Opelousas, LA
  • Average pressure in September: 29.96"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).

Average wind speed in September
Opelousas, LA

Average wind speed in September - Opelousas, LA
  • Average wind speed in September: 5.1mph

The windiest month (with the highest average wind speed) is February (7.9mph).
The calmest month (with the lowest average wind speed) is July (5mph).

Average humidity in September
Opelousas, LA

Average humidity in September - Opelousas, LA
  • Average humidity in September: 80%

The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is October (72%).

Average rainfall in September
Opelousas, LA

Average rainfall in September - Opelousas, LA
  • Average rainfall in September: 0.75"

The wettest months (with the highest rainfall) are July and August (1.57").
The driest months (with the least rainfall) are February and March (0.63").

Average rainfall days in September
Opelousas, LA

Average rainfall days in September - Opelousas, LA
  • Average rainfall days in September: 13.1 days

The month with the highest number of rainy days is August (15.9 days).
The month with the least rainy days is November (6.6 days).

Average snowfall in September
Opelousas, LA

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

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

Average snowfall days in September
Opelousas, LA

Average snowfall days in September - Opelousas, LA
  • Average snowfall days in September: 0 days

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

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

Average daylight in September / Average sunshine in September - Opelousas, 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: 9h and 2min

The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is December (Average sunshine: 4h and 54min).

Average sunshine days in September
Opelousas, LA

Average sunshine days in September - Opelousas, LA
  • Average sunshine days in September: 13.8 days

The month with the most sunshine days is November (21.9 days).
The month with the least sunshine days is August (10.7 days).

Average UV index in September
Opelousas, LA

Average UV index in September - Opelousas, 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
Opelousas, LA

Average cloud cover in September - Opelousas, LA
  • Average cloud cover in September: 34

The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is October (Cloud cover 28).

Average visibility in September
Opelousas, LA

Average visibility in September - Opelousas, LA
  • Average visibility in September: 5mi

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

Opelousas, Louisiana, USA

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