September weather forecast
Baton Rouge, LA

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Manicured lawns and beautiful trees approaching the State Capitol building in Baton Rouge, Louisiana
Manicured lawns and beautiful trees approaching the State Capitol building in Baton Rouge, Louisiana

Weather in September

With the arrival of September, Baton Rouge begins its transition from summer to fall. The city witnesses a trickle of improved weather as temperatures slowly decline. The daily hours of sunshine stabilize at around 9.5 hours, still leaving Baton Rouge with plenty of daylight. The abating heat from the summer months presents September with a marginally reduced relative humidity. Baton Rouge welcomes a steady wind speed of 4.6mph (7.4km/h), offering slight respite from the receding heat.

Temperature

September brings a marginal elevation to a still hot 88°F (31.1°C) from August's 91.9°F (33.3°C) in Baton Rouge's average high-temperatures. In Baton Rouge, the September nights cool down to an average low of 70°F (21.1°C).

Heat index

September's average heat index is estimated at a scorching 105.8°F (41°C). Incorporate additional preventive steps, heat exhaustion and heat cramps are possible. Long-lasting activity may cause heatstroke.
Regarding the heat index, one should be aware it's determined by shaded settings and mild winds. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'real feel' or 'feels like', is a calculation that merges air temperature and relative humidity to depict the sensation of warmth. The impact of weather on an individual can be subjective, affected by the person's activity and heat perception, which can vary due to elements including wind, clothing, and metabolic differences. Consider that direct sun exposure can intensify the felt heat, adding potentially 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are quite important for children. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.
When faced with excessive heat, the human body begins to perspire, utilizing the cooling benefits of sweat evaporation. When relative humidity is heightened, it slows the rate of evaporation, thereby decreasing the body's ability to shed heat and creating a sensation of overheating. Rising body temperatures due to excess heat retention could signify impending heat disorders.

Humidity

In Baton Rouge, the average relative humidity in September is 78%.

Rainfall

In Baton Rouge, during September, the rain falls for 17.6 days and regularly aggregates up to 2.95" (75mm) of precipitation. Throughout the year, there are 177.1 rainfall days, and 36.1" (917mm) of precipitation is accumulated.

Snowfall

February through November are months without snowfall.

Daylight

In Baton Rouge, the average length of the day in September is 12h and 20min.
On the first day of September, sunrise is at 6:41 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:50 pm CDT.

Sunshine

In Baton Rouge, the average sunshine in September is 9.5h.

UV index

In Baton Rouge, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum high UV index of 6 in September translates into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. The time between 10 a.m. and 4 p.m. is when UV radiation is at its peak. Limit exposure to direct sunlight during these hours. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.

Frequently asked questions

How hot is September?

September temperatures in Baton Rouge vary between a high-temperature of 88°F (31.1°C) and a low-temperature of 70°F (21.1°C). In September, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines air temperature and relative humidity, is estimated at 105.8°F (41°C).

What is the average humidity in September in Baton Rouge?

In Baton Rouge, the average relative humidity in September is 78%.

How much does it rain in September?

In Baton Rouge, in September, it is raining for 17.6 days, with typically 2.95" (75mm) of accumulated precipitation.

When it does not snow?

February through November are months without snowfall.

How many hours of daylight does Baton Rouge 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 6:41 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:50 pm CDT.

How many hours of sunshine does Baton Rouge have in September?

In September, the average sunshine duration is 9.5h.

What is the UV index reading in September?

In Baton Rouge, 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
Baton Rouge, LA

Average temperature in September - Baton Rouge, LA
  • Average high temperature in September: 88°F

The warmest months (with the highest average high temperature) are July and August (91.9°F).
The month with the lowest average high temperature is January (58.6°F).

  • Average low temperature in September: 70°F

The month with the highest average low temperature is August (73.9°F).
The coldest month (with the lowest average low temperature) is January (42.4°F).

Average pressure in September
Baton Rouge, LA

Average pressure in September - Baton Rouge, LA
  • Average pressure in September: 29.97"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The months with the lowest atmospheric pressure are June and August (29.96"Hg).

Average wind speed in September
Baton Rouge, LA

Average wind speed in September - Baton Rouge, LA
  • Average wind speed in September: 4.6mph

The windiest month (with the highest average wind speed) is February (6.6mph).
The calmest month (with the lowest average wind speed) is July (4.4mph).

Average humidity in September
Baton Rouge, LA

Average humidity in September - Baton Rouge, LA
  • Average humidity in September: 78%

The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is October (72%).

Average rainfall in September
Baton Rouge, LA

Average rainfall in September - Baton Rouge, LA
  • Average rainfall in September: 2.95"

The wettest month (with the highest rainfall) is July (4.72").
The driest month (with the least rainfall) is November (1.77").

Average rainfall days in September
Baton Rouge, LA

Average rainfall days in September - Baton Rouge, LA
  • Average rainfall days in September: 17.6 days

The month with the highest number of rainy days is July (22.5 days).
The month with the least rainy days is November (8.8 days).

Average snowfall in September
Baton Rouge, LA

Average snowfall in September - Baton Rouge, LA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (0.28").
The months with the least snowfall are February, March, April, May, June, July, August, September, October and November (0").

Average snowfall days in September
Baton Rouge, LA

Average snowfall days in September - Baton Rouge, 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
Baton Rouge, LA

Average daylight in September / Average sunshine in September - Baton Rouge, 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 3min

The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).

Average sunshine days in September
Baton Rouge, LA

Average sunshine days in September - Baton Rouge, LA
  • Average sunshine days in September: 10.4 days

The month with the most sunshine days is November (19.6 days).
The months with the least sunshine days are July and August (7.3 days).

Average UV index in September
Baton Rouge, LA

Average UV index in September - Baton Rouge, LA
  • Average UV index in September: 6

The months with the highest UV index are May, 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
Baton Rouge, LA

Average cloud cover in September - Baton Rouge, LA
  • Average cloud cover in September: 34

The months with the most cloud cover are February and December (Cloud cover 50).
The month with the least cloud cover is October (Cloud cover 29).

Average visibility in September
Baton Rouge, LA

Average visibility in September - Baton Rouge, LA
  • Average visibility in September: 5mi

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

Baton Rouge, Louisiana, USA

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