September weather forecastWilliamsville, NY
September
Weather in September
The first month of the autumn, September, is also an agreeable month in Williamsville, New York, with an average temperature fluctuating between 71.8°F (22.1°C) and 55°F (12.8°C).Temperature
Williamsville's September weather shows a modest shift in high-temperatures, falling from August's warm 78.1°F (25.6°C) to a pleasant 71.8°F (22.1°C). In September, the average low-temperature is a cool 55°F (12.8°C).Humidity
In September, the average relative humidity in Williamsville is 76%.Rainfall
The month with the least rainfall in Williamsville is September, when the rain falls for 11.3 days and typically collects 0.91" (23mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:40 am and sunset at 7:49 pm. On the last day of September, sunrise is at 7:11 am and sunset at 6:57 pm EDT.
Sunshine
The average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes 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 transforms into these recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. Boost your sun resistance with garments that are densely woven yet spacious.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Williamsville, NY
- Average high temperature in September: 71.8°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in September: 55°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 (18.7°F).
Average pressure in September
Williamsville, NY
- Average pressure in September: 30.04"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Williamsville, NY
- Average wind speed in September: 6.9mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest month (with the lowest average wind speed) is July (6.5mph).
Average humidity in September
Williamsville, NY
- Average humidity in September: 76%
The months with the highest relative humidity are January and February (86%).
The months with the lowest relative humidity are July and August (75%).
Average rainfall in September
Williamsville, NY
- Average rainfall in September: 0.91"
The wettest month (with the highest rainfall) is July (1.61").
The driest month (with the least rainfall) is September (0.91").
Average rainfall days in September
Williamsville, NY
- Average rainfall days in September: 11.3 days
The month with the highest number of rainy days is July (15.8 days).
The month with the least rainy days is February (6.4 days).
Average snowfall in September
Williamsville, NY
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (2.95").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Williamsville, NY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (15.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Williamsville, NY
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 9h and 0min
The months with the most sunshine are July and August (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 2h and 24min).
Average sunshine days in September
Williamsville, NY
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is September (15.5 days).
The month with the least sunshine days is February (10.2 days).
Average UV index in September
Williamsville, NY
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February and December (UV index 1).
Average cloud cover in September
Williamsville, NY
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 77).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Williamsville, NY
- Average visibility in September: 6mi
The months with the highest visibility are April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and March (5mi).





