September weather forecastSleepy Hollow, WY
September
Weather in September
The first month of the autumn, September, is still a warm month in Sleepy Hollow, Wyoming, with an average temperature ranging between min 54.3°F (12.4°C) and max 73.6°F (23.1°C).Temperature
September signifies a minor drop in average high-temperature, transitioning from 82.4°F (28°C) in August to a still moderately hot 73.6°F (23.1°C). The average low-temperature, in September, is a fresh 54.3°F (12.4°C).Humidity
In September, the average relative humidity is 44%.Rainfall
In Sleepy Hollow, in September, during 10.2 rainfall days, 1.02" (26mm) of precipitation is typically accumulated. In Sleepy Hollow, Wyoming, during the entire year, the rain falls for 108.9 days and collects up to 15.59" (396mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.4 snowfall days, it receives 0.31" (8mm) of snow. In Sleepy Hollow, during the entire year, snow falls for 50.5 days and aggregates up to 19.53" (496mm) of snow.Daylight
In Sleepy Hollow, the average length of the day in September is 12h and 30min.On the first day of the month, sunrise is at 6:25 am and sunset at 7:37 pm. On the last day of September, sunrise is at 6:59 am and sunset at 6:43 pm MDT.
Sunshine
In Sleepy Hollow, the average sunshine in September is 10.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the average person.Note: In September, the UV index of 4 transforms into the following advice:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Sleepy Hollow, WY
- Average high temperature in September: 73.6°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is December (29.7°F).
- Average low temperature in September: 54.3°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is February (16.7°F).
Average pressure in September
Sleepy Hollow, WY
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Sleepy Hollow, WY
- Average wind speed in September: 10.1mph
The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest months (with the lowest average wind speed) are July and August (9.1mph).
Average humidity in September
Sleepy Hollow, WY
- Average humidity in September: 44%
The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is August (41%).
Average rainfall in September
Sleepy Hollow, WY
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is May (3.11").
The driest month (with the least rainfall) is January (0.39").
Average rainfall days in September
Sleepy Hollow, WY
- Average rainfall days in September: 10.2 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is February (1.5 days).
Average snowfall in September
Sleepy Hollow, WY
- Average snowfall in September: 0.31"
The month with the highest snowfall is April (3.82").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Sleepy Hollow, WY
- Average snowfall days in September: 0.4 days
The month with the highest number of snowfall days is February (9.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Sleepy Hollow, WY
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 10h and 48min
The months with the most sunshine are July and August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 36min).
Average sunshine days in September
Sleepy Hollow, WY
- Average sunshine days in September: 16.4 days
The month with the most sunshine days is December (22.4 days).
The month with the least sunshine days is May (9.3 days).
Average UV index in September
Sleepy Hollow, WY
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, April, November and December (UV index 2).
Average cloud cover in September
Sleepy Hollow, WY
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 43).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in September
Sleepy Hollow, WY
- 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).
