September weather forecastHarvey, LA
September
Weather in September
September, the first month of the autumn in Harvey, is still a hot month, with an average temperature varying between 76.3°F (24.6°C) and 86.5°F (30.3°C).Temperature
Harvey's shift into September is marked by a subtle change to a still hot 86.5°F (30.3°C) from August's 89.4°F (31.9°C) in temperature. Harvey experiences an average nighttime temperature of 76.3°F (24.6°C) in the month of September.Heat index
In September, the heat index is appraised at a fiery hot 98.6°F (37°C). Ensure extra safety steps, heat exhaustion and heat cramps are likely. Long activity might lead to heatstroke.It is crucial to understand that heat index figures are for shade and gentle wind conditions. The heat index has the potential to rise by 15 Fahrenheit (8 Celsius) degrees with direct sunshine exposure.
Note: The heat index, also known as 'apparent temperature' or 'feels like', evaluates the perceived heat by adding the effect of moisture in the air. 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. Being aware that direct sunlight can impact the felt heat might mean an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Typically, young kids are at a higher risk than adults since they sweat less. Also, the larger skin surface in proportion to their small bodies and the heightened heat production due to their active nature adds to their vulnerability.
The natural method the human body uses to remove excess heat is by perspiring and letting sweat evaporate. Augmented relative humidity impedes typical body cooling mechanisms by lowering the evaporation rate, resulting in decreased body cooling and an amplified perception of heat. Overheating and potential dehydration arise when body heat gain eclipses its release capability.
Humidity
In Harvey, the average relative humidity in September is 73%.Rainfall
In Harvey, in September, it is raining for 11.7 days, with typically 0.47" (12mm) of accumulated precipitation. Throughout the year, there are 112.1 rainfall days, and 9.37" (238mm) of precipitation is accumulated.Snowfall
In Harvey, snow does not fall in February through December.Daylight
In Harvey, the average length of the day in September is 12h and 20min.On the first day of September, sunrise is at 6:37 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:53 am and sunset at 6:46 pm CDT.
Sunshine
In Harvey, the average sunshine in September is 10.1h.UV index
May through September, with an average maximum UV index of 7, are months with the highest UV index in Harvey. A UV Index reading of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum UV index of 7 during September translates into these guidelines:
Endorse precautions and be consistent with sun safety guidelines. Preventing sunburn is paramount. The Sun's UV radiation is at its strongest between the hours of 10 a.m. and 4 p.m. Minimize direct exposure to the sun during this period. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Harvey, LA
- Average high temperature in September: 86.5°F
The warmest months (with the highest average high temperature) are July and August (89.4°F).
The month with the lowest average high temperature is January (60.4°F).
- Average low temperature in September: 76.3°F
The month with the highest average low temperature is August (79.5°F).
The coldest month (with the lowest average low temperature) is January (48.6°F).
Average pressure in September
Harvey, 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, August and September (29.97"Hg).
Average wind speed in September
Harvey, LA
- Average wind speed in September: 7.1mph
The windiest months (with the highest average wind speed) are February and April (9.8mph).
The calmest month (with the lowest average wind speed) is July (6.6mph).
Average humidity in September
Harvey, LA
- Average humidity in September: 73%
The months with the highest relative humidity are February and December (77%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Harvey, LA
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is July (1.57").
The driest months (with the least rainfall) are March and April (0.43").
Average rainfall days in September
Harvey, LA
- Average rainfall days in September: 11.7 days
The month with the highest number of rainy days is August (17.2 days).
The month with the least rainy days is November (4.7 days).
Average snowfall days in September
Harvey, LA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.1 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
Harvey, LA
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 14h and 0min).
The month with the shortest days is December (Average daylight: 10h and 18min).
- Average sunshine in September: 10h and 6min
The month with the most sunshine is June (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).
Average sunshine days in September
Harvey, LA
- Average sunshine days in September: 12.5 days
The month with the most sunshine days is November (23.5 days).
The month with the least sunshine days is August (8.9 days).
Average UV index in September
Harvey, LA
- Average UV index in September: 7
The months with the highest UV index are May, June, July, August and September (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Harvey, LA
- Average cloud cover in September: 25
The month with the most cloud cover is December (Cloud cover 44).
The month with the least cloud cover is October (Cloud cover 24).
Average visibility in September
Harvey, 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).





