Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September's arrival brings an average high-temperature of a still tropical 86.9°F (30.5°C), slightly deviating from August's 90.3°F (32.4°C). During September, Atherton observes a consistent average nighttime temperature of 67.8°F (19.9°C).Heat index
For September, the heat index is evaluated at a sweltering 98.6°F (37°C). Exercise more precautions, heat cramps and heat exhaustion are potential risks. Continuous activity could precipitate heatstroke.Heat index values are typically calculated for conditions of shade and a light breeze. Heat index values may be hiked up by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. One's perception of temperature is subjective, varying based on their activity and individual heat perception, influenced by factors like wind, clothing, and metabolic variations. It is noteworthy that being in direct sunlight can enhance the weather's impact, raising the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Children usually face more risks than adults as their ability to sweat is less. Additionally, their larger skin surface in relation to their petite bodies and higher heat output due to their activities increases their vulnerability.
In high temperatures, perspiration kicks in, allowing the human body to cool down through the evaporation of sweat. In conditions of both high temperature and humidity (a high heat index), sweating is limited and the perception of heat is enhanced. The body faces dehydration threats when its cooling efforts are outpaced by excessive heat gain.
Humidity
In September, the average relative humidity is 72%.Rainfall
September is the month with the least rainfall. Rain falls for 12 days and accumulates 1.85" (47mm) of precipitation.Snowfall
April through December are months without snowfall.Daylight
In September, the average length of the day is 12h and 22min.On the first day of September, sunrise is at 6:39 am and sunset at 7:28 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:50 pm CDT.
Sunshine
In Atherton, the average sunshine in September is 10.1h.UV index
In September, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for average individuals.Note: The maximum UV index, 6 during September, leads to the following recommendations:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Try to minimize direct Sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Also note that objects like parasols or canopies might not provide complete sun protection. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the average humidity in September?
What is the driest month?
How many days does it rain in September?
When it does not snow?
How many hours of daylight does Atherton have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Atherton have in September?
How high is the UV index in September?
Average temperature in September
Atherton, LA
- Average high temperature in September: 86.9°F
The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is January (53.1°F).
- Average low temperature in September: 67.8°F
The month with the highest average low temperature is July (73.4°F).
The coldest month (with the lowest average low temperature) is January (39.2°F).
Average pressure in September
Atherton, LA
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).
Average wind speed in September
Atherton, LA
- Average wind speed in September: 5.6mph
The windiest month (with the highest average wind speed) is February (9.1mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in September
Atherton, LA
- Average humidity in September: 72%
The month with the highest relative humidity is February (80%).
The month with the lowest relative humidity is October (67%).
Average rainfall in September
Atherton, LA
- Average rainfall in September: 1.85"
The wettest month (with the highest rainfall) is April (4.41").
The driest month (with the least rainfall) is September (1.85").
Average rainfall days in September
Atherton, LA
- Average rainfall days in September: 12 days
The month with the highest number of rainy days is July (16.7 days).
The month with the least rainy days is October (9.5 days).
Average snowfall in September
Atherton, LA
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (0.16").
The months with the least snowfall are April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Atherton, LA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.8 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Atherton, LA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 10h and 1min
The month with the most sunshine is June (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).
Average sunshine days in September
Atherton, LA
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is October (20.5 days).
The month with the least sunshine days is July (12.2 days).
Average UV index in September
Atherton, 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
Atherton, LA
- Average cloud cover in September: 27
The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is June (Cloud cover 25).
Average visibility in September
Atherton, LA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Atherton, Louisiana, USA
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