September weather forecastGaines Mill, VA
September
Weather in September
September, the first month of the autumn in Gaines Mill, is also a moderately hot month, with an average temperature varying between 81.3°F (27.4°C) and 63.3°F (17.4°C).Temperature
As August transitions into September, Gaines Mill sees a gentle drop in the average high-temperature, transitioning from a tropical 88°F (31.1°C) to a warm 81.3°F (27.4°C). During September, Gaines Mill sees a mean low-temperature of 63.3°F (17.4°C).Heat index
The heat index for September is computed to be a hot 86°F (30°C). If one continues to be active during exposure, it might cause tiredness and subsequent heat cramps.Understanding the heat index involves considering values for shaded locales with light wind. The heat index values could be amplified by up to 15 Fahrenheit (8 Celsius) degrees in direct sunlight.
Note: The heat index, also known as 'feels like' or 'real feel', is an amalgamation of air temperature and humidity to express the equivalent perceived temperature. A person's impression of weather can be shaped by several aspects, among them metabolic variations, pregnancy, and levels of physical activity. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Children frequently underestimate the necessity to rest and hydrate. Thirst is a late sign of dehydration - thus, it is vital to stay hydrated, particularly during lengthy physical exercises.
Humidity
The average relative humidity in September in Gaines Mill is 74%.Rainfall
September is the month with the least rainfall in Gaines Mill. Rain falls for 10.5 days and accumulates 1.1" (28mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
The average length of the day in September is 12h and 25min.On the first day of September in Gaines Mill, sunrise is at 6:40 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:53 pm EDT.
Sunshine
In September, the average sunshine in Gaines Mill is 8.7h.UV index
In Gaines Mill, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The average daily UV index of 5 in September transforms into the following instructions:
Take necessary precautions - Protection from skin and eye injury is mandatory. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Gaines Mill, VA
- Average high temperature in September: 81.3°F
The warmest month (with the highest average high temperature) is July (90.3°F).
The month with the lowest average high temperature is January (44.8°F).
- Average low temperature in September: 63.3°F
The month with the highest average low temperature is July (69.8°F).
The coldest month (with the lowest average low temperature) is January (29.7°F).
Average pressure in September
Gaines Mill, VA
- Average pressure in September: 30.04"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Gaines Mill, VA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is April (7.5mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in September
Gaines Mill, VA
- Average humidity in September: 74%
The month with the highest relative humidity is December (78%).
The month with the lowest relative humidity is July (69%).
Average rainfall in September
Gaines Mill, VA
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is August (2.05").
The driest month (with the least rainfall) is September (1.1").
Average rainfall days in September
Gaines Mill, VA
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is May (14.8 days).
The months with the least rainy days are October and November (8.2 days).
Average snowfall in September
Gaines Mill, VA
- Average snowfall in September: 0"
The month with the highest snowfall is March (0.67").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Gaines Mill, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Gaines Mill, VA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The months with the least sunshine are February and December (Average sunshine: 5h and 12min).
Average sunshine days in September
Gaines Mill, VA
- Average sunshine days in September: 18.6 days
The months with the most sunshine days are October and December (21.4 days).
The month with the least sunshine days is May (14.4 days).
Average UV index in September
Gaines Mill, VA
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
Gaines Mill, VA
- Average cloud cover in September: 39
The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in September
Gaines Mill, VA
- 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).





