September weather forecastVan Alstyne, TX
September
Weather in September
September, the first month of the autumn in Van Alstyne, is still a hot month, with temperature in the range of an average low of 68.5°F (20.3°C) and an average high of 86.2°F (30.1°C).Temperature
The start of September involves a subtle temperature drop, shifting from a tropical 94.3°F (34.6°C) in August to a still hot 86.2°F (30.1°C). Van Alstyne experiences an average low-temperature of 68.5°F (20.3°C) in the month of September.Heat index
September's average heat index is estimated at a tropical 93.2°F (34°C). Undertake extra safety actions, heat cramps and heat exhaustion are expected. Heatstroke may result from lengthy activity.Remember that heat index calculations are made for conditions in the shade with light wind. The heat index has the potential to rise by 15 Fahrenheit (8 Celsius) degrees with direct sunshine exposure.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is a metric representing the sensation of warmth when air temperature and moisture come together. An individual's perception of weather can be swayed by a variety of elements including metabolic differences, pregnancy status, and their level of physical exertion. Keep it in mind, direct sunlight can augment the heat you experience, possibly pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Children often fail to recognize the requirement to rest and rehydrate. Thirst, being a late symptom of dehydration, underlines the importance of maintaining hydration, especially during ongoing physical activities.
Humidity
The average relative humidity in September is 66%.Rainfall
In September, the rain falls for 14.4 days. Throughout September, 3.19" (81mm) of precipitation is accumulated. In Van Alstyne, during the entire year, the rain falls for 142.1 days and collects up to 33.19" (843mm) of precipitation.Snowfall
In Van Alstyne, Texas, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 7:00 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 7:11 pm CDT.
Sunshine
In September, the average sunshine in Van Alstyne is 8.5h.UV index
The average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: A maximum high UV index of 6 in September translates into the following recommendations:
Adopt measures and apply sun safety strategies. Shielding from skin and eye damage is necessary. Remember that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. Make an effort to avoid direct sun exposure during these hours. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Van Alstyne, TX
- Average high temperature in September: 86.2°F
The warmest month (with the highest average high temperature) is August (94.3°F).
The month with the lowest average high temperature is January (52.3°F).
- Average low temperature in September: 68.5°F
The month with the highest average low temperature is August (74.8°F).
The coldest month (with the lowest average low temperature) is January (36.5°F).
Average pressure in September
Van Alstyne, TX
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Van Alstyne, TX
- Average wind speed in September: 7mph
The windiest month (with the highest average wind speed) is March (10.4mph).
The calmest month (with the lowest average wind speed) is September (7mph).
Average humidity in September
Van Alstyne, TX
- Average humidity in September: 66%
The month with the highest relative humidity is May (77%).
The month with the lowest relative humidity is August (59%).
Average rainfall in September
Van Alstyne, TX
- Average rainfall in September: 3.19"
The wettest month (with the highest rainfall) is October (4.21").
The driest month (with the least rainfall) is January (1.61").
Average rainfall days in September
Van Alstyne, TX
- Average rainfall days in September: 14.4 days
The month with the highest number of rainy days is May (15.4 days).
The month with the least rainy days is January (7.2 days).
Average snowfall in September
Van Alstyne, TX
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.71").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Van Alstyne, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.4 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
Van Alstyne, TX
- Average daylight in September: 12h and 24min
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: 8h and 30min
The month with the most sunshine is August (Average sunshine: 11h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).
Average sunshine days in September
Van Alstyne, TX
- Average sunshine days in September: 14.9 days
The month with the most sunshine days is January (22.3 days).
The month with the least sunshine days is May (13.8 days).
Average UV index in September
Van Alstyne, 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 2).
Average cloud cover in September
Van Alstyne, TX
- Average cloud cover in September: 29
The months with the most cloud cover are February and March (Cloud cover 41).
The month with the least cloud cover is August (Cloud cover 21).
Average visibility in September
Van Alstyne, 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).





