September weather forecastSouth Alamo, TX
September
Weather in September
The first month of the autumn, September, is also a hot month in South Alamo, Texas, with temperature in the range of an average low of 77.2°F (25.1°C) and an average high of 92.5°F (33.6°C).Temperature
With the arrival of September, South Alamo experiences a modest decline in average high-temperatures, transitioning from a fiery hot 98.2°F (36.8°C) in August to a hot 92.5°F (33.6°C). South Alamo's temperature tends to fall to an average low of 77.2°F (25.1°C) during the nights of September.Heat index
During September, the heat index is calculated to be a blisteringly hot 109.4°F (43°C). Be alert: Heat exhaustion along with heat cramps are probable. Heatstroke is a threat with sustained physical activity.Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', combines both the air temperature and the humidity level to give a perceived human temperature. An individual's temperature experience can be influenced by extra factors, including metabolic differences, activity levels, and clothing. With direct sunlight, be aware that it might enhance the heat sensation, raising the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Youngsters typically face more danger than adults since they sweat less. Their larger skin surface compared to their small bodies and heightened heat production from their activities augment their vulnerability.
The physiological way the human body responds to excessive heat is by inducing perspiration, using sweat evaporation as a cooling mechanism. An increase in relative humidity hinders the body's normal cooling function by reducing evaporation, thereby decreasing the rate of body cooling and enhancing the sense of warmth. Accumulating heat beyond the body's cooling measures leads to rising temperatures and potential ailments.
Humidity
In South Alamo, the average relative humidity in September is 65%.Rainfall
The month with the most rainfall is September, when the rain falls for 15.1 days and typically aggregates up to 1.46" (37mm) of precipitation.Snowfall
In South Alamo, Texas, snow does not fall in February through December.Daylight
The average length of the day in September is 12h and 18min.On the first day of September, sunrise is at 7:12 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:19 pm CDT.
Sunshine
The average sunshine in September is 8.6h.UV index
In September, the average daily maximum UV index is 7. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 7 during September translates into the following guidance:
Prevent overexposure. Protection from the sun's harmful effects is needed. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun protection. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
South Alamo, TX
- Average high temperature in September: 92.5°F
The warmest month (with the highest average high temperature) is August (98.2°F).
The month with the lowest average high temperature is January (69.6°F).
- Average low temperature in September: 77.2°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 (53.4°F).
Average pressure in September
South Alamo, TX
- Average pressure in September: 29.91"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are May and June (29.87"Hg).
Average wind speed in September
South Alamo, TX
- Average wind speed in September: 8.9mph
The windiest month (with the highest average wind speed) is May (12.4mph).
The calmest month (with the lowest average wind speed) is September (8.9mph).
Average humidity in September
South Alamo, TX
- Average humidity in September: 65%
The month with the highest relative humidity is May (69%).
The month with the lowest relative humidity is August (59%).
Average rainfall in September
South Alamo, TX
- Average rainfall in September: 1.46"
The wettest month (with the highest rainfall) is September (1.46").
The driest months (with the least rainfall) are January and February (0.31").
Average rainfall days in September
South Alamo, TX
- Average rainfall days in September: 15.1 days
The month with the highest number of rainy days is September (15.1 days).
The month with the least rainy days is February (5.4 days).
Average snowfall in September
South Alamo, TX
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.12").
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
South Alamo, TX
- 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
South Alamo, TX
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 13h and 48min).
The month with the shortest days is December (Average daylight: 10h and 30min).
- Average sunshine in September: 8h and 36min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in September
South Alamo, TX
- Average sunshine days in September: 12.5 days
The month with the most sunshine days is July (23 days).
The month with the least sunshine days is September (12.5 days).
Average UV index in September
South Alamo, TX
- Average UV index in September: 7
The months with the highest UV index are July and August (UV index 8).
The month with the lowest UV index is December (UV index 4).
Average cloud cover in September
South Alamo, TX
- Average cloud cover in September: 30
The month with the most cloud cover is December (Cloud cover 39).
The month with the least cloud cover is August (Cloud cover 18).
Average visibility in September
South Alamo, 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).
