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
In Grottoes, the beginning of September is marked by a marginally lowered average high-temperature, shifting from August's 82.9°F (28.3°C) to a still warm 76.1°F (24.5°C). During the nights in September, Grottoes experiences a consistent average temperature of 55.6°F (13.1°C).Humidity
May, September and October, with an average relative humidity of 78%, are the most humid months.Rainfall
In Grottoes, Virginia, in September, it is raining for 14.1 days, with typically 2.2" (56mm) of accumulated precipitation. Throughout the year, there are 164.3 rainfall days, and 30.08" (764mm) of precipitation is accumulated.Snowfall
In Grottoes, snow does not fall in June through September.Daylight
In Grottoes, the average length of the day in September is 12h and 25min.On the first day of September in Grottoes, sunrise is at 6:45 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:59 pm EDT.
Sunshine
The average sunshine in September in Grottoes is 8.6h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: In September, the maximum UV index of 4 suggests this advice:
Ensure safety - Imperative it is to shield skin and eyes from damage. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Frequently asked questions
What is the usual temperature for Grottoes in September?
What are the most humid months in Grottoes?
What is the average humidity in September in Grottoes?
How much does it rain in Grottoes in September?
When it does not snow in Grottoes?
Does it snow in Grottoes in September?
What is the average length of the day in September in Grottoes?
What time are sunrise and sunset in September in Grottoes?
How many hours of sunshine does Grottoes have in September?
What is the UV index reading in September in Grottoes?
Average temperature in September
Grottoes, VA
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (84.6°F).
The month with the lowest average high temperature is January (39°F).
- Average low temperature in September: 55.6°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Grottoes, VA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).
Average wind speed in September
Grottoes, VA
- Average wind speed in September: 4.5mph
The windiest months (with the highest average wind speed) are February and April (6.6mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).
Average humidity in September
Grottoes, VA
- Average humidity in September: 78%
The months with the highest relative humidity are May, September and October (78%).
The months with the lowest relative humidity are January, June and July (74%).
Average rainfall in September
Grottoes, VA
- Average rainfall in September: 2.2"
The wettest month (with the highest rainfall) is May (3.27").
The driest month (with the least rainfall) is January (1.89").
Average rainfall days in September
Grottoes, VA
- Average rainfall days in September: 14.1 days
The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is November (8.6 days).
Average snowfall in September
Grottoes, VA
- Average snowfall in September: 0"
The month with the highest snowfall is March (4.53").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Grottoes, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (6.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Grottoes, VA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
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 18min).
Average sunshine days in September
Grottoes, VA
- Average sunshine days in September: 13.8 days
The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in September
Grottoes, VA
- Average UV index in September: 4
The months with the highest UV index are May, June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Grottoes, VA
- Average cloud cover in September: 39
The month with the most cloud cover is March (Cloud cover 46).
The months with the least cloud cover are June and July (Cloud cover 31).
Average visibility in September
Grottoes, VA
- Average visibility in September: 5mi
The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).
Grottoes, Virginia, USA
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