September weather forecast
Grand River, LA

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Weather in September

September, the first month of the autumn in Grand River, is also a hot month, with an average temperature ranging between min 70.3°F (21.3°C) and max 87.3°F (30.7°C).

Temperature

September's presence marks an average high-temperature of a still hot 87.3°F (30.7°C), subtly varied from August's 91.2°F (32.9°C). In September, the recorded average low-temperature is an agreeable 70.3°F (21.3°C).

Heat index

In September, the heat index is estimated at a blistering 104°F (40°C). Exercise increased caution, heat cramps and heat exhaustion are potential hazards. Continuous activity could lead to heatstroke.
Remember that heat index calculations are made for conditions in the shade with light wind. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is a numerical representation of warmth when taking temperature and moisture levels into account. Factors such as metabolic variation, pregnancy, and physical activity play a role in one's impression of weather. Take note that direct exposure to the sun can increase the felt temperature, possibly adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are quite important for babies and toddlers. Children often overlook the necessity for resting and fluid replenishment. Thirst is a late sign of dehydration - thus, it is critical to stay hydrated, especially during extended periods of physical activities.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. When the air contains significant moisture, the efficiency of the evaporation process decreases, preventing the body from cooling down effectively and creating a feeling of overheating. The body is at risk of dehydration and related complications when it fails to shed excessive heat.

Humidity

The average relative humidity in September is 79%.

Rainfall

In Grand River, during September, the rain falls for 16 days and regularly aggregates up to 1.18" (30mm) of precipitation. Throughout the year, there are 148.6 rainfall days, and 15.51" (394mm) of precipitation is accumulated.

Snowfall

In Grand River, 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 September, sunrise is at 6:42 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:51 pm CDT.

Sunshine

In Grand River, the average sunshine in September is 9.7h.

UV index

In September, the average daily maximum UV index in Grand River is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: The UV index of 6 during September leads to these advisories:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. Remember that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. Make an effort to avoid direct sun exposure during these hours. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Updated: Jun 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot is September?

During September, Grand River experiences an average high-temperature of 87.3°F (30.7°C) and a low-temperature of 70.3°F (21.3°C). In September, the average heat index (a.k.a. 'feels like', 'felt air temperature'), which combines relative humidity and air temperature, is estimated at 104°F (40°C).

What is the average humidity in September?

The average relative humidity in September is 79%.

How many days does it rain in September?

In Grand River, in September, during 16 rainfall days, 1.18" (30mm) of precipitation is typically accumulated.

When it does not snow?

In Grand River, snow does not fall in February through December.

How many hours of daylight does Grand River have in September?

In Grand River, 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 6:42 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:51 pm CDT.

How many hours of sunshine does Grand River have in September?

In September, the average sunshine duration is 9.7h.

What is the UV index reading in September?

The average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from 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
Grand River, LA

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

The warmest months (with the highest average high temperature) are July and August (91.2°F).
The month with the lowest average high temperature is January (59°F).

  • Average low temperature in September: 70.3°F

The month with the highest average low temperature is August (74.5°F).
The coldest month (with the lowest average low temperature) is January (43.5°F).

Average pressure in September
Grand River, LA

Average pressure in September - Grand River, 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
Grand River, LA

Average wind speed in September - Grand River, LA
  • Average wind speed in September: 4.7mph

The windiest month (with the highest average wind speed) is February (6.9mph).
The calmest months (with the lowest average wind speed) are July and August (4.5mph).

Average humidity in September
Grand River, LA

Average humidity in September - Grand River, 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 (73%).

Average rainfall in September
Grand River, LA

Average rainfall in September - Grand River, LA
  • Average rainfall in September: 1.18"

The wettest month (with the highest rainfall) is July (2.56").
The driest month (with the least rainfall) is March (0.67").

Average rainfall days in September
Grand River, LA

Average rainfall days in September - Grand River, LA
  • Average rainfall days in September: 16 days

The month with the highest number of rainy days is August (20.9 days).
The month with the least rainy days is November (7.1 days).

Average snowfall in September
Grand River, LA

Average snowfall in September - Grand River, LA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (0.08").
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
Grand River, LA

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

Average daylight in September /
Average sunshine in September
Grand River, LA

Average daylight in September / Average sunshine in September - Grand River, 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 4min

The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).

Average sunshine days in September
Grand River, LA

Average sunshine days in September - Grand River, LA
  • Average sunshine days in September: 11.3 days

The month with the most sunshine days is November (21.4 days).
The months with the least sunshine days are July and August (7.3 days).

Average UV index in September
Grand River, LA

Average UV index in September - Grand River, LA
  • Average UV index in September: 6

The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).

Average cloud cover in September
Grand River, LA

Average cloud cover in September - Grand River, LA
  • Average cloud cover in September: 31

The months with the most cloud cover are February and December (Cloud cover 47).
The month with the least cloud cover is October (Cloud cover 27).

Average visibility in September
Grand River, LA

Average visibility in September - Grand River, LA
  • Average visibility in September: 5mi

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

Grand River, Louisiana, USA

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