September weather forecastCastleton, VT
September
Weather in September
September brings a noticeable change in the weather pattern in Castleton, Vermont. The weather conditions show autumn slowly settling in, dropping the average high temperature to 69.8°F (21°C). The rainfall reduces to 0.67in, and the sunlight hours decrease, indicating the onset of shorter days. Cooler evenings start becoming a norm, signaling the changing of seasons. The decrease in temperature provides a respite from the summer heat, offering the perfect weather to enjoy the beautiful fall colors in the city.Temperature
The shift from August to September includes a small decrease in the average high-temperature, from a warm 77.4°F (25.2°C) to a pleasant 69.8°F (21°C). September's average low-temperature reading in Castleton settles at a chilly 49.3°F (9.6°C).Humidity
The average relative humidity in September in Castleton is 79%.Rainfall
The months with the least rainfall are March and September Rain falls for 8 days and accumulates 0.67" (17mm) of rain.Snowfall
In Castleton, snow does not fall in June through September.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:17 am and sunset at 7:27 pm. On the last day of September, in Castleton, sunrise is at 6:49 am and sunset at 6:35 pm EDT.
Sunshine
In Castleton, the average sunshine in September is 8.6h.UV index
In Castleton, the average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for the average person.Note: The UV index of 3 during September leads to these advisories:
Undertake protective steps - Preventing sun damage is advised. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Castleton, VT
- Average high temperature in September: 69.8°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 (25.2°F).
- Average low temperature in September: 49.3°F
The month with the highest average low temperature is July (56.8°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).
Average pressure in September
Castleton, VT
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Castleton, VT
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is April (7.1mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in September
Castleton, VT
- Average humidity in September: 79%
The months with the highest relative humidity are January and February (86%).
The months with the lowest relative humidity are April and May (75%).
Average rainfall in September
Castleton, VT
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is June (1.22").
The driest months (with the least rainfall) are March and September (0.67").
Average rainfall days in September
Castleton, VT
- Average rainfall days in September: 8 days
The month with the highest number of rainy days is May (12.8 days).
The month with the least rainy days is January (4.5 days).
Average snowfall in September
Castleton, VT
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.11").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Castleton, VT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (11.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Castleton, VT
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 8h and 36min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 3h and 18min).
Average sunshine days in September
Castleton, VT
- Average sunshine days in September: 19.4 days
The month with the most sunshine days is November (20.5 days).
The month with the least sunshine days is February (15.6 days).
Average UV index in September
Castleton, VT
- Average UV index in September: 3
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Castleton, VT
- Average cloud cover in September: 38
The month with the most cloud cover is February (Cloud cover 64).
The months with the least cloud cover are July and August (Cloud cover 36).
Average visibility in September
Castleton, VT
- Average visibility in September: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).
