September weather forecastViola, DE
September
Weather in September
September is a transitional month in Viola, Delaware as summer gives way to fall. Although temperatures start to descend with an average high of 76.5°F (24.7°C), the month remains fairly warm. The fall of leaves marks the beginning of the autumn season in all its vibrance. As daylight hours start to dwindle, nights become longer, bringing forth milder weather towards the end of the month. Despite the cooling trend, sunshine persists, allowing for continued outdoor activity.Temperature
The shift from August to September coincides with a small decrease in the average high-temperature, down to a still moderately hot 76.5°F (24.7°C) from 82.2°F (27.9°C). The nighttime temperature, during September, averages of 63.1°F (17.3°C).Humidity
The months with the highest humidity are May, August and September, with an average relative humidity of 79%.Rainfall
In Viola, in September, it is raining for 13.6 days, with typically 2.44" (62mm) of accumulated precipitation. In Viola, during the entire year, the rain falls for 167.5 days and collects up to 35.35" (898mm) of precipitation.Snowfall
In Viola, snow does not fall in May through October.Daylight
The average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:32 pm. On the last day of September, sunrise is at 6:58 am and sunset at 6:46 pm EDT.
Sunshine
In Viola, the average sunshine in September is 9.2h.UV index
In September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum daily UV index, 5 in September, converts into the following recommendations:
Adopt protective measures - It is advised to guard against sun damage. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Viola, DE
- Average high temperature in September: 76.5°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (40.3°F).
- Average low temperature in September: 63.1°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 (28.8°F).
Average pressure in September
Viola, DE
- Average pressure in September: 30.04"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Viola, DE
- Average wind speed in September: 7.3mph
The windiest month (with the highest average wind speed) is February (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity in September
Viola, DE
- Average humidity in September: 79%
The months with the highest relative humidity are May, August and September (79%).
The months with the lowest relative humidity are January, March, April and November (74%).
Average rainfall in September
Viola, DE
- Average rainfall in September: 2.44"
The wettest month (with the highest rainfall) is August (3.9").
The driest month (with the least rainfall) is January (2.13").
Average rainfall days in September
Viola, DE
- Average rainfall days in September: 13.6 days
The month with the highest number of rainy days is July (18.8 days).
The month with the least rainy days is November (9 days).
Average snowfall in September
Viola, DE
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.93").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Viola, DE
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.3 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
Viola, DE
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 12min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).
Average sunshine days in September
Viola, DE
- Average sunshine days in September: 13.9 days
The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is July (9.7 days).
Average UV index in September
Viola, DE
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
Viola, DE
- Average cloud cover in September: 34
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Viola, DE
- 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).
