September weather forecastLeague City, TX
September
Weather in September
September signifies the beginning of autumn in League City, with temperatures dropping to span from 75.7°F (24.3°C) to 86.2°F (30.1°C). September witnesses the highest rainfall of the year, mapping at 1.5" (38mm). Despite the rainfall, the decrease in temperature and humidity along with prolonged daylight hours offer perfect conditions for outdoor events and picnics. As September advances, the cool autumn evenings add a certain charm to the city’s lively atmosphere. The gradual shift from the sweltering heat of summer to the pleasant coolness of autumn makes September a delightful month.Temperature
With the start of September, League City measures an average high-temperature of a still hot 86.2°F (30.1°C), not significantly differing from August's 90.5°F (32.5°C). League City, in September, witnesses an average low-temperature of 75.7°F (24.3°C).Heat index
The heat index for September is evaluated at a very hot 98.6°F (37°C). Implement more safety precautions, heat cramps and heat exhaustion may happen. Persistent activity could induce heatstroke.Heat index readings emphasize conditions of light breezes and shaded spots. Facing direct sunlight may hike up the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', reflects the blend of air temperature and relative humidity to give a temperature impression. The impact of weather is individual, with diverse individuals experiencing it differently due to variations in body mass, height, and activity levels. With the sun shining directly, it's crucial to understand that it can increase the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Youngsters frequently overlook the need for breaks and fluid intake. Thirst is an advanced sign of dehydration - thereby highlighting the importance of keeping hydrated, particularly during long physical activities.
In the face of high temperatures, the human body's reflex is to perspire, leveraging sweat evaporation for cooling. An elevated level of relative humidity hinders evaporation, leading to decreased heat elimination from the body, inducing a sensation of excess heat. When heat uptake goes beyond the body's cooling mechanisms, there's a surge in body temperature, posing health risks.
Humidity
In League City, Texas, the average relative humidity in September is 75%.Rainfall
September is the month with the most rainfall in League City. Rain falls for 15.9 days and accumulates 1.5" (38mm) of precipitation.Snowfall
Months with snowfall are January, September and December. The months with the most snowfall days are January, September and December, with an average of 0.1 snowfall days.Daylight
In September, the average length of the day is 12h and 20min.On the first day of the month, sunrise is at 6:58 am and sunset at 7:42 pm. On the last day of September, in League City, sunrise is at 7:13 am and sunset at 7:06 pm CDT.
Sunshine
In September, the average sunshine is 8.6h.UV index
In League City, the average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: A daily high UV index of 6 in September leads to these guidelines:
Evade overexposure. Individuals with fair skin risk burning in under 20 minutes. The Sun emits the most powerful UV radiation between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Be vigilant! The reflective nature of snow can increase the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
League City, TX
- Average high temperature in September: 86.2°F
The warmest month (with the highest average high temperature) is August (90.5°F).
The month with the lowest average high temperature is January (60.4°F).
- Average low temperature in September: 75.7°F
The month with the highest average low temperature is August (79.7°F).
The coldest month (with the lowest average low temperature) is January (48.6°F).
Average pressure in September
League City, 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
League City, TX
- Average wind speed in September: 7.7mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (7.6mph).
Average humidity in September
League City, TX
- Average humidity in September: 75%
The month with the highest relative humidity is February (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
League City, TX
- Average rainfall in September: 1.5"
The wettest month (with the highest rainfall) is September (1.5").
The driest months (with the least rainfall) are February and March (0.31").
Average rainfall days in September
League City, TX
- Average rainfall days in September: 15.9 days
The month with the highest number of rainy days is September (15.9 days).
The month with the least rainy days is February (6.3 days).
Average snowfall days in September
League City, TX
- Average snowfall days in September: 0.1 days
The months with the highest number of snowfall days are January, September and December (0.1 days).
The months with the least snowfall days are February, March, April, May, June, July, August, October and November (0 days).
Average daylight in September /
Average sunshine in September
League City, TX
- 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: 8h and 36min
The months with the most sunshine are July and August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 42min).
Average sunshine days in September
League City, TX
- Average sunshine days in September: 10.3 days
The month with the most sunshine days is January (21.9 days).
The month with the least sunshine days is September (10.3 days).
Average UV index in September
League City, 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
League City, TX
- Average cloud cover in September: 31
The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in September
League City, 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).





