September weather forecastSan Leon, TX
September
Weather in September
The first month of the autumn, September, is still a warm month in San Leon, Texas, with an average temperature fluctuating between 76.8°F (24.9°C) and 85.5°F (29.7°C).Temperature
San Leon records an average high-temperature of a moderately hot 85.5°F (29.7°C) as September arrives, nearly mirroring the previous month's climate. San Leon records a negligible downturn from daytime temperatures, averaging a low of 76.8°F (24.9°C) in the month of September.Heat index
For September, the heat index is calculated to be a very hot 95°F (35°C). More protective measures are required - heat exhaustion and heat cramps are likely. Heatstroke may follow lengthy activity.Note that heat index values are valued for light wind and location in the shade. A rise in the heat index by 15 Fahrenheit (8 Celsius) degrees may result from direct sunlight exposure.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is a single figure representing how weather conditions feel when combining temperature and humidity. Elements such as metabolic variations, being pregnant, and physical activity can impact one's weather perception. Take note that direct exposure to the sun can increase the felt temperature, possibly adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are quite important for babies and toddlers. Young individuals usually face more risks than adults due to their lower sweat production. Their large skin surface area relative to their tiny bodies and high heat production from their activities adds to their risk.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. An increase in relative humidity disrupts body cooling by slowing the evaporation rate, thereby reducing the rate at which the body cools and amplifying the sense of heat. When heat uptake goes beyond the body's cooling mechanisms, there's a surge in body temperature, posing health risks.
Humidity
The average relative humidity in September in San Leon is 75%.Rainfall
September is the month with the most rainfall. Rain falls for 20.5 days and accumulates 6.77" (172mm) of precipitation.Snowfall
In San Leon, snow does not fall in February through December.Ocean temperature
In September, the average ocean temperature is 83.8°F (28.8°C).Note: Water temperature ranging between 77°F (25°C) and 84.2°F (29°C) is considered very warm and pleasing for everyone. It allows for enjoyable water activities over extended periods without discomfort.
Daylight
In San Leon, the average length of the day in September is 12h and 20min.On the first day of September, sunrise is at 6:57 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 7:06 pm CDT.
Sunshine
In San Leon, the average sunshine in September is 8.9h.UV index
In San Leon, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for average individuals.Note: The UV index of 6 during September leads to these advisories:
Deter overexposure. Protecting against the sun's effects is essential. Avoid direct Sun exposure and seek shade from 10 a.m. to 4 p.m., the period of highest UV radiation. Remember, however, that not all shade structures offer full protection. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears. Heads up! The reflection of sand and water notably intensifies UV rays from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
San Leon, TX
- Average high temperature in September: 85.5°F
The warmest month (with the highest average high temperature) is August (89.2°F).
The month with the lowest average high temperature is January (59.5°F).
- Average low temperature in September: 76.8°F
The months with the highest average low temperature are July and August (80.2°F).
The coldest month (with the lowest average low temperature) is January (49.5°F).
Average pressure in September
San Leon, 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
San Leon, TX
- Average wind speed in September: 8.3mph
The windiest month (with the highest average wind speed) is April (11.4mph).
The calmest months (with the lowest average wind speed) are August and September (8.3mph).
Average humidity in September
San Leon, TX
- Average humidity in September: 75%
The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
San Leon, TX
- Average rainfall in September: 6.77"
The wettest month (with the highest rainfall) is September (6.77").
The driest month (with the least rainfall) is March (1.81").
Average rainfall days in September
San Leon, TX
- Average rainfall days in September: 20.5 days
The month with the highest number of rainy days is August (22.1 days).
The month with the least rainy days is November (11.6 days).
Average snowfall in September
San Leon, TX
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.04").
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
San Leon, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).
Average sea temperature in September
San Leon, TX
- Average sea temperature in September: 83.8°F
The best month for swimming (with the highest average sea temperature) is August (87.2°F).
The coldest month (with the lowest average sea temperature) is January (56.5°F).
Average daylight in September /
Average sunshine in September
San Leon, 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 54min
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 54min).
Average sunshine days in September
San Leon, 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 August (6.3 days).
Average UV index in September
San Leon, 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
San Leon, TX
- Average cloud cover in September: 30
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is June (Cloud cover 27).
Average visibility in September
San Leon, 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).
