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
With the arrival of September, San Antonio notices a mild change in the average high-temperature, sliding from August's very hot 96.6°F (35.9°C) to a hot 89.1°F (31.7°C). San Antonio experiences an average low-temperature of 71.6°F (22°C) in the month of September.Heat index
Throughout September, the heat index is estimated at a very hot 100.4°F (38°C). Adopt extra preventive measures, the occurrence of heat cramps and heat exhaustion is likely. Heatstroke may follow extended activity.Take note of the fact that heat index values are based on shaded circumstances with light airflows. 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', is derived by integrating air temperature with the existing relative humidity to express the perceived warmth. This effect is subjective, differing among individuals based on their physical activity and perception of heat, which can be influenced by factors like wind, clothing, and metabolic variances. The sun, when shining directly, can have a significant impact on the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young ones generally face higher dangers than adults since they sweat less. Along with their large skin surface area compared totheir small bodies and increased heat production from their activities, the risks are heightened.
To cool down, the human body relies on perspiration, a process where excessive heat is eliminated as sweat evaporates. Heightened relative humidity interferes with the body's usual cooling mechanism by reducing evaporation, subsequently decreasing the body's cooling rate and increasing the sensation of heat. When body temperature rises due to excess heat gain beyond its removal capability, one might experience heat-related disorders.
Humidity
The average relative humidity in September is 66%.Rainfall
In September, in San Antonio, the rain falls for 17 days. Throughout September, 3.39" (86mm) of precipitation is accumulated. In San Antonio, during the entire year, the rain falls for 144.5 days and collects up to 22.6" (574mm) of precipitation.Snowfall
March through November are months without snowfall in San Antonio, Texas.Daylight
In San Antonio, the average length of the day in September is 12h and 20min.On the first day of the month, sunrise is at 7:11 am and sunset at 7:55 pm. On the last day of September, in San Antonio, sunrise is at 7:27 am and sunset at 7:20 pm CDT.
Sunshine
In September, the average sunshine is 8.4h.UV index
In San Antonio, Texas, the average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for the ordinary person.Note: In September, a regular UV index of 6 translates into these guidelines:
Undertake precautions and comply with sun safety standards. Protection from skin and eye injury is vital. Avoid direct Sun exposure and seek shade between 10 a.m. and 4 p.m., when UV radiation is at its peak, but keep in mind that not all shade structures provide complete protection. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Frequently asked questions
How hot is September in San Antonio?
What is the average humidity in September in San Antonio?
How many days does it rain in September in San Antonio?
When it does not snow in San Antonio?
How many hours of daylight does San Antonio have in September?
When is the sunrise / sunset in September in San Antonio?
How many hours of sunshine does San Antonio have in September?
What is the UV index reading in September in San Antonio?
Average temperature in September
San Antonio, TX
- Average high temperature in September: 89.1°F
The warmest month (with the highest average high temperature) is August (96.6°F).
The month with the lowest average high temperature is January (61.7°F).
- Average low temperature in September: 71.6°F
The month with the highest average low temperature is August (75.7°F).
The coldest month (with the lowest average low temperature) is January (44.2°F).
Average pressure in September
San Antonio, TX
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
San Antonio, TX
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is May (9mph).
The calmest month (with the lowest average wind speed) is September (6.5mph).
Average humidity in September
San Antonio, TX
- Average humidity in September: 66%
The month with the highest relative humidity is May (73%).
The month with the lowest relative humidity is August (59%).
Average rainfall in September
San Antonio, TX
- Average rainfall in September: 3.39"
The wettest month (with the highest rainfall) is May (3.66").
The driest month (with the least rainfall) is February (0.98").
Average rainfall days in September
San Antonio, TX
- Average rainfall days in September: 17 days
The month with the highest number of rainy days is September (17 days).
The month with the least rainy days is January (9.1 days).
Average snowfall in September
San Antonio, TX
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (0.08").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
San Antonio, TX
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
San Antonio, 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 2min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in September
San Antonio, TX
- Average sunshine days in September: 11.8 days
The month with the most sunshine days is January (20.3 days).
The months with the least sunshine days are May and September (11.8 days).
Average UV index in September
San Antonio, TX
- Average UV index in September: 6
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
San Antonio, TX
- Average cloud cover in September: 33
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in September
San Antonio, 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).
San Antonio, Texas, USA
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