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
The onset of September is marked by a minor decrease in temperature, transitioning from a moderately hot 82.8°F (28.2°C) in August to a still warm 77°F (25°C). Nighttime temperature in Vienna experiences an average drop to an enjoyable 63.1°F (17.3°C) in September.Humidity
The months with the highest humidity in Vienna are May, August and September, with an average relative humidity of 80%.Rainfall
In Vienna, in September, during 10.3 rainfall days, 0.98" (25mm) of precipitation is typically accumulated. In Vienna, Maryland, during the entire year, the rain falls for 114.4 days and collects up to 12.05" (306mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In Vienna, the average length of the day in September is 12h and 25min.On the first day of September in Vienna, sunrise is at 6:33 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:47 pm EDT.
Sunshine
In Vienna, the average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: The UV index of 5 in September translates into these instructions:
Ensure safety - Imperative it is to shield skin and eyes from damage. The solar radiation around mid-day is intense; avoid the Sun and stay safe. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Frequently asked questions
What is the temperature in September in Vienna?
What is the most humid month in Vienna?
What is the average humidity in September in Vienna?
How much does it rain in Vienna in September?
When it does not snow in Vienna?
What is the average length of the day in September in Vienna?
When are sunrise and sunset in September in Vienna?
How many hours of sunshine does Vienna have in September?
What is the UV index reading in September in Vienna?
Average temperature in September
Vienna, MD
- Average high temperature in September: 77°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (42.1°F).
- Average low temperature in September: 63.1°F
The month with the highest average low temperature is July (70.2°F).
The coldest month (with the lowest average low temperature) is January (29.5°F).
Average pressure in September
Vienna, MD
- 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
Vienna, MD
- Average wind speed in September: 7.1mph
The windiest month (with the highest average wind speed) is February (9.7mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity in September
Vienna, MD
- Average humidity in September: 80%
The months with the highest relative humidity are May, August and September (80%).
The months with the lowest relative humidity are January, February, March and April (75%).
Average rainfall in September
Vienna, MD
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is July (1.46").
The driest months (with the least rainfall) are April and May (0.79").
Average rainfall days in September
Vienna, MD
- Average rainfall days in September: 10.3 days
The month with the highest number of rainy days is July (13.2 days).
The month with the least rainy days is November (6.5 days).
Average snowfall in September
Vienna, MD
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.75").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Vienna, MD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (3.2 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
Vienna, MD
- 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 30min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The months with the least sunshine are February and December (Average sunshine: 5h and 6min).
Average sunshine days in September
Vienna, MD
- Average sunshine days in September: 17 days
The month with the most sunshine days is November (21.2 days).
The month with the least sunshine days is July (14.7 days).
Average UV index in September
Vienna, MD
- 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
Vienna, MD
- Average cloud cover in September: 35
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in September
Vienna, MD
- 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).
Vienna, Maryland, USA
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