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
In the transition to September, San Marcos observes a minor drop in the average high-temperature, shifting from a very hot 95.9°F (35.5°C) in August to a hot 88°F (31.1°C). An average minimum temperature of 70.5°F (21.4°C) marks the month of September in San Marcos.Heat index
Throughout September, the heat index is evaluated at a very hot 100.4°F (38°C). Exercise enhanced safety steps, heat cramps and heat exhaustion are probable. Heatstroke could be a result of sustained activity.Heat index values are typically calculated for conditions of shade and a light breeze. Heat index values can rise by 15 Fahrenheit (8 Celsius) degrees when in direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'feels like', gauges the sensation of temperature factoring in the air's moisture content. The individual's impression of temperature can be shaped by additional aspects such as metabolic variations, physical activity, and clothing. It is noteworthy that being in direct sunlight can enhance the weather's impact, raising the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Children often overlook the necessity for resting and fluid replenishment. Thirst is a late sign of dehydration - thus, it is critical to stay hydrated, especially during extended periods of physical activities.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. Under conditions of high relative humidity, the rate of evaporation decreases. This results in the body retaining more heat than under conditions of dry air. If heat absorption isn't effectively countered by the body's cooling methods, body temperature surges, hinting at potential problems.
Humidity
In San Marcos, the average relative humidity in September is 70%.Rainfall
In San Marcos, in September, it is raining for 15.5 days, with typically 3.62" (92mm) of accumulated precipitation. Throughout the year, there are 151.8 rainfall days, and 26.89" (683mm) of precipitation is accumulated.Snowfall
In San Marcos, snow does not fall in March through November.Daylight
In September, the average length of the day is 12h and 20min.On the first day of September in San Marcos, Texas, sunrise is at 7:09 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 7:18 pm CDT.
Sunshine
The average sunshine in September is 8.3h.UV index
In September, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the average person.Note: In September, the maximum UV index of 6 suggests this advice:
Undertake precautions and comply with sun safety standards. Protection from skin and eye injury is vital. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Frequently asked questions
How hot is September in San Marcos?
What is the average humidity in September in San Marcos?
How much does it rain in San Marcos in September?
When it does not snow in San Marcos?
How many hours of daylight does San Marcos have in September?
When are sunrise and sunset in September in San Marcos?
How long on average sun shines in September in San Marcos?
What is the UV index intensity in September in San Marcos?
Average temperature in September
San Marcos, TX
- Average high temperature in September: 88°F
The warmest month (with the highest average high temperature) is August (95.9°F).
The month with the lowest average high temperature is January (59.9°F).
- Average low temperature in September: 70.5°F
The month with the highest average low temperature is August (74.7°F).
The coldest month (with the lowest average low temperature) is January (42.8°F).
Average pressure in September
San Marcos, TX
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
San Marcos, TX
- Average wind speed in September: 6.1mph
The windiest month (with the highest average wind speed) is February (9.1mph).
The calmest month (with the lowest average wind speed) is September (6.1mph).
Average humidity in September
San Marcos, TX
- Average humidity in September: 70%
The month with the highest relative humidity is May (77%).
The month with the lowest relative humidity is August (62%).
Average rainfall in September
San Marcos, TX
- Average rainfall in September: 3.62"
The wettest month (with the highest rainfall) is May (4.57").
The driest month (with the least rainfall) is February (1.1").
Average rainfall days in September
San Marcos, TX
- Average rainfall days in September: 15.5 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is January (9.4 days).
Average snowfall in September
San Marcos, TX
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (0.12").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
San Marcos, 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 Marcos, 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 months with the most sunshine are July and August (Average sunshine: 10h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 12min).
Average sunshine days in September
San Marcos, TX
- Average sunshine days in September: 12.4 days
The month with the most sunshine days is January (19.4 days).
The month with the least sunshine days is May (11.9 days).
Average UV index in September
San Marcos, 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 Marcos, TX
- Average cloud cover in September: 34
The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in September
San Marcos, TX
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
San Marcos, Texas, USA
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