September weather forecast
Geismar, LA

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Weather in September

The first month of the autumn, September, is still a tropical month in Geismar, Louisiana, with temperature in the range of an average high of 87.4°F (30.8°C) and an average low of 70.5°F (21.4°C).

Temperature

The ushering in of September brings an average high-temperature of a still hot 87.4°F (30.8°C), closely mirroring the 90.7°F (32.6°C) of August. In Geismar, the September nights cool down to an average low of 70.5°F (21.4°C).

Heat index

The average heat index in September is appraised at a blisteringly hot 104°F (40°C). Take more safety measures, heat exhaustion and heat cramps are potential outcomes. Persistent activity might lead to heatstroke.
It is crucial to understand that heat index figures are for shade and gentle wind conditions. The heat index can potentially augment by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a single figure representing how weather conditions feel when combining temperature and humidity. Factors such as metabolic variations, being pregnant, and physical activity can impact an individual's weather perception. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Young ones often do not realize the necessity to rest and replenish their fluids. Thirst is a delayed indication of dehydration - keeping hydrated, particularly in prolonged physical activity, is crucial.
The body's self-cooling mechanism is rooted in perspiration, where evaporating sweat cools down excessive warmth. Under high air temperature and high humidity (high heat index) conditions, the body's ability to perspire is compromised, increasing the sensation of heat. Overheating and dehydration threats arise when heat gain goes beyond what the body can comfortably shed.

Humidity

In September, the average relative humidity is 79%.

Rainfall

In September, the rain falls for 14.9 days. Throughout September, 1.18" (30mm) of precipitation is accumulated. Throughout the year, there are 151.5 rainfall days, and 18.62" (473mm) of precipitation is accumulated.

Snowfall

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

Daylight

The average length of the day in September is 12h and 20min.
On the first day of the month, sunrise is at 6:41 am and sunset at 7:26 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:50 pm CDT.

Sunshine

In Geismar, the average sunshine in September is 9.9h.

UV index

The average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for average individuals.
Note: In September, the UV index of 6 transforms into the following advice:
Eschew overexposure. Those with light skin may suffer burns in fewer than 20 minutes. Seek shade and limit direct Sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its peak, but be aware that not all shade structures provide complete sun protection. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.

Frequently asked questions

How hot is it in September?

An average high-temperature, in September, in Geismar, is 87.4°F (30.8°C) and the average low-temperature is 70.5°F (21.4°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, in September is appraised at 104°F (40°C).

What is the average humidity in September?

In September, the average relative humidity is 79%.

How much does it rain in September?

In Geismar, in September, it is raining for 14.9 days, with typically 1.18" (30mm) of accumulated precipitation.

When it does not snow?

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

How many hours of daylight does Geismar have in September?

In September, the average day length is 12h and 20min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:41 am and sunset at 7:26 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 Geismar have in September?

The average sunshine duration in September is 9.9h.

What is the UV index intensity in September?

In Geismar, Louisiana, the average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents 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
Geismar, LA

Average temperature in September - Geismar, LA
  • Average high temperature in September: 87.4°F

The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is January (59.2°F).

  • Average low temperature in September: 70.5°F

The month with the highest average low temperature is August (74.8°F).
The coldest month (with the lowest average low temperature) is January (43.5°F).

Average pressure in September
Geismar, LA

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

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

Average wind speed in September
Geismar, LA

Average wind speed in September - Geismar, LA
  • Average wind speed in September: 4.9mph

The windiest months (with the highest average wind speed) are February and April (7.1mph).
The calmest months (with the lowest average wind speed) are July and August (4.7mph).

Average humidity in September
Geismar, LA

Average humidity in September - Geismar, LA
  • Average humidity in September: 79%

The months with the highest relative humidity are February and December (81%).
The month with the lowest relative humidity is October (74%).

Average rainfall in September
Geismar, LA

Average rainfall in September - Geismar, LA
  • Average rainfall in September: 1.18"

The wettest month (with the highest rainfall) is July (3.03").
The driest months (with the least rainfall) are March and November (0.98").

Average rainfall days in September
Geismar, LA

Average rainfall days in September - Geismar, LA
  • Average rainfall days in September: 14.9 days

The month with the highest number of rainy days is July (18.9 days).
The month with the least rainy days is November (7.9 days).

Average snowfall in September
Geismar, LA

Average snowfall in September - Geismar, LA
  • 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
Geismar, LA

Average snowfall days in September - Geismar, LA
  • 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 February, March, April, May, June, July, August, September, October, November and December (0 days).

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

Average daylight in September / Average sunshine in September - Geismar, 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 5min

The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).

Average sunshine days in September
Geismar, LA

Average sunshine days in September - Geismar, LA
  • Average sunshine days in September: 12.9 days

The month with the most sunshine days is November (20.4 days).
The month with the least sunshine days is August (9.3 days).

Average UV index in September
Geismar, LA

Average UV index in September - Geismar, 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
Geismar, LA

Average cloud cover in September - Geismar, LA
  • Average cloud cover in September: 29

The month with the most cloud cover is December (Cloud cover 47).
The month with the least cloud cover is October (Cloud cover 26).

Average visibility in September
Geismar, LA

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

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

Geismar, Louisiana, USA

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