September weather forecast
Geismar, LA

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Weather in September

September, the first month of the autumn in Geismar, is still a tropical month, with an average temperature ranging between min 70.5°F (21.4°C) and max 87.4°F (30.8°C).

Temperature

The introduction of September notes a subtle temperature variation to a still hot 87.4°F (30.8°C) from August's 90.7°F (32.6°C). In September, Geismar experiences an average nighttime temperature of 70.5°F (21.4°C).

Heat index

The heat index value during September is calculated to be a blisteringly hot 104°F (40°C). Ensure extra safety measures, heat exhaustion and heat cramps are likely. Continuous activity might result in heatstroke.
Data suggests that the heat index is set for environments in shade and with a light wind. An exposure to direct sunlight may lift the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. A person's impression of weather can be shaped by many aspects, among them metabolic variations, pregnancy, and levels of physical activity. Sunshine, when direct, has the potential to intensify weather effects, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. 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.
As a reaction to high temperatures, the human body begins to perspire, using the evaporation of sweat to lower its temperature. Under high air temperature and high humidity (high heat index) conditions, the body's ability to perspire is compromised, increasing the sensation of heat. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

In Geismar, the average relative humidity in September is 79%.

Rainfall

In September, in Geismar, 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

In Geismar, the average length of the day in September is 12h and 20min.
On the first day of September in Geismar, 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.

Sunshine

In September, the average sunshine is 9.9h.

UV index

In September, the average daily maximum UV index in Geismar is 6. A UV Index estimate of 6 to 7 represents a high threat to health from exposure to the Sun's UV rays for average individuals.
Note: The UV index of 6 in September translates into these instructions:
Stand by precautions and apply sun safety measures. Evading sunburn is of great importance. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
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Frequently asked questions

Is it hot in Geismar during September?

During September, Geismar experiences an average high-temperature of 87.4°F (30.8°C) and a low-temperature of 70.5°F (21.4°C). The average heat index (a.k.a. 'real feel', 'feels like'), which combines relative humidity and air temperature, in September is calculated to be 104°F (40°C).

What is the average humidity in September in Geismar?

The average relative humidity in September is 79%.

How many days does it rain in September in Geismar?

In Geismar, Louisiana, during September, the rain falls for 14.9 days and regularly aggregates up to 1.18" (30mm) of precipitation.

When it does not snow in Geismar?

February through December are months without snowfall in Geismar, Louisiana.

What is the average length of the day in September in Geismar?

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

What time are sunrise and sunset in September in Geismar?

On the first day of September, 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?

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

How high is the UV index in September in Geismar?

In September, the average daily maximum UV index is 6. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to Sun's UV rays.
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).

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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).

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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).

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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%).

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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").

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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).

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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").

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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).

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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).

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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).

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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).

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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).

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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).

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Geismar, Louisiana, USA

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