September weather forecastWilliamson, WV
September
Weather in September
September offers a welcome respite from the relentless summer heat, signifying the start of the balmy fall season. The temperatures begin to fall, averaging between 56.8°F (13.8°C) and 78.6°F (25.9°C). A slight nip can be felt in the air, especially during the nights. The leaves start to change color, casting a lovely palette over Williamson. Despite the decreasing temperatures, the city continues to have a fair share of sunny days.Temperature
September in Williamson is characterized by a mild reduction in the average high-temperature, from 84.4°F (29.1°C) in August to a still warm 78.6°F (25.9°C). Williamson logs a substantial downturn to a moderate 56.8°F (13.8°C) during September nights, a considerable shift from daytime highs.Humidity
In September, the average relative humidity is 76%.Rainfall
The month with the least rainfall is September, when the rain falls for 12.5 days and typically collects 1.46" (37mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:59 am and sunset at 7:57 pm. On the last day of September, sunrise is at 7:24 am and sunset at 7:13 pm EDT.
Sunshine
In September, the average sunshine is 8.3h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index of 4 during September translates into the following directions:
Prioritize safety - Recommendations to avert sunburn are shared. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Williamson, WV
- Average high temperature in September: 78.6°F
The warmest month (with the highest average high temperature) is July (86°F).
The month with the lowest average high temperature is January (40.1°F).
- Average low temperature in September: 56.8°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (26.8°F).
Average pressure in September
Williamson, WV
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in September
Williamson, WV
- Average wind speed in September: 4.2mph
The windiest month (with the highest average wind speed) is April (6.4mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).
Average humidity in September
Williamson, WV
- Average humidity in September: 76%
The month with the highest relative humidity is February (81%).
The months with the lowest relative humidity are July, August and November (75%).
Average rainfall in September
Williamson, WV
- Average rainfall in September: 1.46"
The wettest months (with the highest rainfall) are February and May (3.27").
The driest month (with the least rainfall) is September (1.46").
Average rainfall days in September
Williamson, WV
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is November (10.1 days).
Average snowfall in September
Williamson, WV
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.09").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Williamson, WV
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Williamson, WV
- Average daylight in September: 12h and 24min
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 18min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Williamson, WV
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is October (17.7 days).
The month with the least sunshine days is May (10.5 days).
Average UV index in September
Williamson, WV
- Average UV index in September: 4
The months with the highest UV index are June and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in September
Williamson, WV
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in September
Williamson, WV
- Average visibility in September: 5mi
The months with the highest visibility are April and November (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October and December (5mi).
