September weather forecastRio, WV
September
Weather in September
The first month of the autumn, September, is still a warm month in Rio, West Virginia, with temperature in the range of an average low of 54°F (12.2°C) and an average high of 75.2°F (24°C).Temperature
September is marked by a subtle drop in average high-temperatures, transitioning from a warm 82.2°F (27.9°C) in August to a still moderately hot 75.2°F (24°C). In Rio, September's nights observe an average temperature dip to a fresh 54°F (12.2°C).Humidity
In September, the average relative humidity is 78%.Rainfall
In Rio, in September, it is raining for 14.5 days, with typically 2.01" (51mm) of accumulated precipitation. Throughout the year, there are 166 rainfall days, and 25.83" (656mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:44 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:58 pm EDT.
Sunshine
In September, the average sunshine in Rio is 9h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the maximum UV index of 4 suggests this advice:
Ensure safety - Sun damage prevention is strongly urged. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rio, WV
- Average high temperature in September: 75.2°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in September: 54°F
The month with the highest average low temperature is July (60.6°F).
The coldest month (with the lowest average low temperature) is January (22.5°F).
Average pressure in September
Rio, WV
- Average pressure in September: 30.06"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
Rio, WV
- Average wind speed in September: 4.3mph
The windiest month (with the highest average wind speed) is February (7.1mph).
The calmest month (with the lowest average wind speed) is August (4mph).
Average humidity in September
Rio, WV
- Average humidity in September: 78%
The month with the highest relative humidity is October (79%).
The months with the lowest relative humidity are April and July (74%).
Average rainfall in September
Rio, WV
- Average rainfall in September: 2.01"
The wettest month (with the highest rainfall) is May (3.11").
The driest months (with the least rainfall) are February and November (1.73").
Average rainfall days in September
Rio, WV
- Average rainfall days in September: 14.5 days
The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is November (9.1 days).
Average snowfall in September
Rio, WV
- Average snowfall in September: 0"
The month with the highest snowfall is March (4.21").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Rio, WV
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Rio, WV
- 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 0min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The months with the least sunshine are January and December (Average sunshine: 5h and 6min).
Average sunshine days in September
Rio, WV
- Average sunshine days in September: 13 days
The month with the most sunshine days is November (18.3 days).
The month with the least sunshine days is May (10.1 days).
Average UV index in September
Rio, WV
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Rio, WV
- Average cloud cover in September: 37
The month with the most cloud cover is January (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Rio, WV
- Average visibility in September: 5mi
The months with the highest visibility are April, June, July, November and December (6mi).
The months with the lowest visibility are January, February, March, May, August, September and October (5mi).
