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
September's onset corresponds with a subtle shift in the average high-temperature, slightly moving from a tropical 88.3°F (31.3°C) in August to a moderately hot 81.3°F (27.4°C). Dumbarton records a mean low-temperature of 62.6°F (17°C) in September.Heat index
The heat index in September is evaluated at a hot 86°F (30°C). Prolonged exposure combined with continuous activity could lead to exhaustion, and possibly heat cramps.Remember that heat index calculations are made for conditions in the shade with light wind. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is a composite of temperature and humidity figures to convey how warm it feels. Factors such as metabolic variations, being pregnant, and physical activity can impact an individual's weather perception. It is essential to realize that direct sunlight can escalate the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Young people are generally more susceptible than adults because they perspire less. Furthermore, their proportionally larger skin surface to their petite bodies and the increased heat output from their actions add to the risk.
Humidity
In September, the average relative humidity in Dumbarton is 73%.Rainfall
The month with the least rainfall in Dumbarton, Virginia, is September, when the rain falls for 12.5 days and typically collects 1.65" (42mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In Dumbarton, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:40 am and sunset at 7:38 pm. On the last day of September, in Dumbarton, Virginia, sunrise is at 7:05 am and sunset at 6:54 pm EDT.
Sunshine
The average sunshine in September is 8.7h.UV index
In Dumbarton, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the average person.Note: The UV index of 5 in September translates into these instructions:
Take measures. Individuals with light skin might experience burns in under 30 minutes. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Frequently asked questions
What is the temperature in September in Dumbarton?
What is the average humidity in September in Dumbarton?
What is the driest month in Dumbarton?
How many days does it rain in September in Dumbarton?
When it does not snow in Dumbarton?
What is the average length of the day in September in Dumbarton?
When is the sunrise / sunset in September in Dumbarton?
How long on average sun shines in September in Dumbarton?
What is the UV index reading in September in Dumbarton?
Average temperature in September
Dumbarton, VA
- Average high temperature in September: 81.3°F
The warmest month (with the highest average high temperature) is July (90.7°F).
The month with the lowest average high temperature is January (44.2°F).
- Average low temperature in September: 62.6°F
The month with the highest average low temperature is July (69.6°F).
The coldest month (with the lowest average low temperature) is January (29.5°F).
Average pressure in September
Dumbarton, 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
Dumbarton, VA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is April (7.4mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in September
Dumbarton, VA
- Average humidity in September: 73%
The month with the highest relative humidity is December (78%).
The month with the lowest relative humidity is July (68%).
Average rainfall in September
Dumbarton, VA
- Average rainfall in September: 1.65"
The wettest month (with the highest rainfall) is August (2.72").
The driest month (with the least rainfall) is September (1.65").
Average rainfall days in September
Dumbarton, VA
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is November (8.8 days).
Average snowfall in September
Dumbarton, VA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.77").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Dumbarton, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.5 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
Dumbarton, VA
- Average daylight in September: 12h and 2min
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 4min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 12min).
Average sunshine days in September
Dumbarton, VA
- Average sunshine days in September: 15.8 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is May (11.9 days).
Average UV index in September
Dumbarton, VA
- Average UV index in September: 5
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in September
Dumbarton, VA
- Average cloud cover in September: 39
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in September
Dumbarton, 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).
Dumbarton, Virginia, USA
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