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
A moderate decline in average high-temperatures is noted in September, moving from a hot 94.3°F (34.6°C) in August to a still tropical 88.3°F (31.3°C). Houston's nights in September experience an average temperature drop to a pleasant 72.7°F (22.6°C).Heat index
Throughout September, the heat index is evaluated at a scorching 104°F (40°C). Exercise extra preventive actions, heat cramps and heat exhaustion are plausible. Continuous activity could result in heatstroke.Always consider that heat index estimations are for light winds and places in the shade. When exposed to the direct sun, the heat index may augment by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', shows a temperature sensation when both heat and moisture conditions are combined. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. Keep it in mind, direct sunlight can augment the heat you experience, possibly pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Typically, children face more danger than adults as they usually perspire less. Their larger skin surface relative to their small bodies and increased heat output from their activities enhance their risk.
Evaporating sweat, an outcome of perspiration, is key in assisting the human body to moderate its temperature. Under high air temperature and humidity (high heat index) conditions, perspiration is limited, and the perception of heat is increased. Heat absorption that surpasses the body's shedding capability can lead to overheating and varying levels of dehydration.
Humidity
In September, the average relative humidity is 74%.Rainfall
September is the month with the most rainfall. Rain falls for 19.5 days and accumulates 4.49" (114mm) of precipitation.Snowfall
In Houston, Texas, snow does not fall in February through November.Daylight
In September, the average length of the day is 12h and 20min.On the first day of the month, sunrise is at 6:59 am and sunset at 7:43 pm. On the last day of September, sunrise is at 7:14 am and sunset at 7:07 pm CDT.
Sunshine
The average sunshine in September in Houston is 8.6h.UV index
In September, the average daily maximum UV index is 6. A UV Index of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for the ordinary person.Note: An average UV index of 6 in September transforms into this advice:
Persist with precautions and heed sun safety advice. Prevention of sunburn is compulsory. 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. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in September?
What is the average humidity in September?
What is the rainiest month?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Houston have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Houston have in September?
What is the UV index intensity in September in Houston?
Average temperature in September
Houston, TX
- Average high temperature in September: 88.3°F
The warmest month (with the highest average high temperature) is August (94.3°F).
The month with the lowest average high temperature is January (61.3°F).
- Average low temperature in September: 72.7°F
The month with the highest average low temperature is August (77.5°F).
The coldest month (with the lowest average low temperature) is January (46°F).
Average pressure in September
Houston, TX
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Houston, TX
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is April (8.6mph).
The calmest month (with the lowest average wind speed) is September (5.9mph).
Average humidity in September
Houston, TX
- Average humidity in September: 74%
The month with the highest relative humidity is February (78%).
The months with the lowest relative humidity are August and October (70%).
Average rainfall in September
Houston, TX
- Average rainfall in September: 4.49"
The wettest month (with the highest rainfall) is September (4.49").
The driest month (with the least rainfall) is February (1.77").
Average rainfall days in September
Houston, TX
- Average rainfall days in September: 19.5 days
The month with the highest number of rainy days is September (19.5 days).
The month with the least rainy days is January (11.8 days).
Average snowfall in September
Houston, TX
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.08").
The months with the least snowfall are February, March, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Houston, TX
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and December (0.1 days).
The months with the least snowfall days are February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Houston, TX
- Average daylight in September: 12h and 2min
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: 8h and 4min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 4h and 48min).
Average sunshine days in September
Houston, TX
- Average sunshine days in September: 7.9 days
The month with the most sunshine days is January (16.3 days).
The month with the least sunshine days is September (7.9 days).
Average UV index in September
Houston, TX
- 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
Houston, TX
- Average cloud cover in September: 32
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Houston, TX
- 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).
Houston, Texas, USA
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