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
A modest decline in the average high-temperature is seen during September, decreasing from a tropical 93.9°F (34.4°C) in August to a still hot 87.3°F (30.7°C). Mount Vernon, in the month of September, anticipates a consistent average low-temperature of 67.1°F (19.5°C).Heat index
In September, the average heat index is estimated at a torrid 98.6°F (37°C). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.Heat index readings emphasize conditions of light breezes and shaded spots. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. The effect is personal, with varied weather perceptions among individuals due to differences in body mass, stature, and physical activity. In direct sunlight, the heat's impact can be heightened, potentially leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Young ones often disregard the necessity to rest and hydrate. Thirst usually indicates advanced dehydration - hence, it is key to stay hydrated, particularly during ongoing physical activities.
The innate cooling system of the human body revolves around perspiration, with the evaporation of sweat being central to this process. With an abundance of moisture present in the air, the process of evaporation becomes less effective, and the body fails to cool down as it should, leading to the sensation of overheating. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.
Humidity
In Mount Vernon, Texas, the average relative humidity in September is 69%.Rainfall
September is the month with the least rainfall. Rain falls for 9.5 days and accumulates 0.59" (15mm) of precipitation.Snowfall
In Mount Vernon, snow does not fall in April through December.Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:55 am and sunset at 7:45 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 7:06 pm CDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: The daily maximum UV index of 6 in September interprets into the following advice:
Resist overexposure. Safeguarding from solar damage is indispensable. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is at its strongest, and remember that parasols or canopies do not offer full protection. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in Mount Vernon in September?
What is the average humidity in September?
What is the driest month?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Mount Vernon have in September?
When are sunrise and sunset in September?
How many hours of sunshine does Mount Vernon have in September?
What is the UV index reading in September?
Average temperature in September
Mount Vernon, TX
- Average high temperature in September: 87.3°F
The warmest month (with the highest average high temperature) is August (93.9°F).
The month with the lowest average high temperature is January (52.9°F).
- Average low temperature in September: 67.1°F
The month with the highest average low temperature is July (73°F).
The coldest month (with the lowest average low temperature) is January (37°F).
Average pressure in September
Mount Vernon, TX
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Mount Vernon, TX
- Average wind speed in September: 5.8mph
The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).
Average humidity in September
Mount Vernon, TX
- Average humidity in September: 69%
The months with the highest relative humidity are February and May (78%).
The month with the lowest relative humidity is August (66%).
Average rainfall in September
Mount Vernon, TX
- Average rainfall in September: 0.59"
The wettest month (with the highest rainfall) is October (1.69").
The driest month (with the least rainfall) is September (0.59").
Average rainfall days in September
Mount Vernon, TX
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is May (11.7 days).
The month with the least rainy days is January (6.9 days).
Average snowfall in September
Mount Vernon, TX
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.35").
The months with the least snowfall are April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Mount Vernon, TX
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (0.9 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Mount Vernon, TX
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is August (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in September
Mount Vernon, TX
- Average sunshine days in September: 18 days
The month with the most sunshine days is October (21.6 days).
The month with the least sunshine days is August (15.8 days).
Average UV index in September
Mount Vernon, TX
- Average UV index in September: 6
The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Mount Vernon, TX
- Average cloud cover in September: 28
The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in September
Mount Vernon, 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).
Mount Vernon, Texas, USA
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