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 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
The transition from August to September brings an average high-temperature of a still hot 88.2°F (31.2°C), barely different from August's 91°F (32.8°C). San Antonio Heights encounters a significant temperature differential, with an average low-temperature of 63.5°F (17.5°C) during September nights.Heat index
The heat index in September is estimated at a tropical 89.6°F (32°C). Persistently participating in activities during exposure may lead to fatigue and induce heat cramps.Heat index readings emphasize conditions of light breezes and shaded spots. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is a single figure representing how weather conditions feel when combining temperature and humidity. The individual's experience of temperature can be shaped by numerous aspects such as metabolic variations, physical exertion, and attire. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Children often do not understand the need to rest and hydrate. Thirst is a late manifestation of dehydration - therefore, it is essential to stay hydrated, particularly during prolonged physical activities.
Humidity
In September, the average relative humidity is 44%.Rainfall
In September, the rain falls for 2.5 days. Throughout September, 0.12" (3mm) of precipitation is accumulated. Throughout the year, there are 49.6 rainfall days, and 7.8" (198mm) of precipitation is accumulated.Snowfall
In San Antonio Heights, snow does not fall in January, March through December.Daylight
The average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:24 am and sunset at 7:16 pm. On the last day of September, sunrise is at 6:45 am and sunset at 6:35 pm PDT.
Sunshine
The average sunshine in September is 10.7h.UV index
The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The UV index of 6 in September translates into these instructions:
Avoid excessive sunlight. Those with lighter skin may experience burning in less than 20 minutes. The Sun's UV radiation is most potent between the hours of 10 a.m. and 4 p.m. Try to avoid direct sunlight during this time. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does San Antonio Heights have in September?
What is the UV index reading in September?
Average temperature in September
San Antonio Heights, CA
- Average high temperature in September: 88.2°F
The warmest month (with the highest average high temperature) is August (91°F).
The month with the lowest average high temperature is December (62.1°F).
- Average low temperature in September: 63.5°F
The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is December (45.5°F).
Average pressure in September
San Antonio Heights, CA
- Average pressure in September: 29.88"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in September
San Antonio Heights, CA
- Average wind speed in September: 4.4mph
The windiest months (with the highest average wind speed) are April and May (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity in September
San Antonio Heights, CA
- Average humidity in September: 44%
The months with the highest relative humidity are March and May (54%).
The month with the lowest relative humidity is August (42%).
Average rainfall in September
San Antonio Heights, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is February (1.77").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
San Antonio Heights, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (7.1 days).
The month with the least rainy days is June (1.2 days).
Average snowfall days in September
San Antonio Heights, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
San Antonio Heights, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 4min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 54min).
Average sunshine days in September
San Antonio Heights, CA
- Average sunshine days in September: 25.4 days
The month with the most sunshine days is June (28.2 days).
The month with the least sunshine days is February (21.5 days).
Average UV index in September
San Antonio Heights, CA
- Average UV index in September: 6
The months with the highest UV index are 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 Heights, CA
- Average cloud cover in September: 6
The month with the most cloud cover is December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
San Antonio Heights, CA
- 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 Heights, California, USA
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