September weather forecastGuernsey, WY
September
Weather in September
September marks the onset of fall in Guernsey, Wyoming, with the average high temperature dropping to 77.2°F (25.1°C) from August's peak, accompanied by a mild increase in rainfall. This shift in weather initiates the transformation of green landscapes into varying shades of autumn hues. As summer recedes, the city begins experiencing pleasant weather - a break from the intense summer heat. September promises cooler evenings under pristine, clear skies, ideal for outdoor pursuits or witnessing marvelous sunset views. The mild weather combined with the beauty of the changing seasons makes this month a popular time to visit Guernsey.Temperature
September's onset brings a negligible change in high-temperatures, falling from 85.6°F (29.8°C) in August to a still warm 77.2°F (25.1°C). Guernsey receives a consistent average low-temperature of 54.3°F (12.4°C) in September, a substantial dip from the day's heat.Humidity
The average relative humidity in September is 40%.Rainfall
In Guernsey, in September, during 7.4 rainfall days, 0.75" (19mm) of precipitation is typically accumulated. Throughout the year, there are 90.8 rainfall days, and 11.57" (294mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows in Guernsey. Throughout September, in the average 0.3 snowfall days, it receives 0.94" (24mm) of snow. In Guernsey, during the entire year, snow falls for 46.4 days and aggregates up to 27.13" (689mm) of snow.Daylight
The average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:25 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 6:41 pm MDT.
Sunshine
In Guernsey, the average sunshine in September is 10.6h.UV index
In September, the average daily maximum UV index in Guernsey is 5. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: The daily high UV index of 5 in September translates into this advice:
Take precautions - Protection against sun damage is advised. Minimize direct exposure to the Sun during midday when its radiation is at its peak. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Guernsey, WY
- Average high temperature in September: 77.2°F
The warmest month (with the highest average high temperature) is July (86.9°F).
The month with the lowest average high temperature is December (35.1°F).
- Average low temperature in September: 54.3°F
The month with the highest average low temperature is July (62.8°F).
The coldest months (with the lowest average low temperature) are February and December (21.6°F).
Average pressure in September
Guernsey, WY
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Guernsey, WY
- Average wind speed in September: 9.6mph
The windiest month (with the highest average wind speed) is January (15mph).
The calmest month (with the lowest average wind speed) is August (8.6mph).
Average humidity in September
Guernsey, WY
- Average humidity in September: 40%
The month with the highest relative humidity is February (66%).
The month with the lowest relative humidity is August (39%).
Average rainfall in September
Guernsey, WY
- Average rainfall in September: 0.75"
The wettest month (with the highest rainfall) is May (1.97").
The driest month (with the least rainfall) is January (0.35").
Average rainfall days in September
Guernsey, WY
- Average rainfall days in September: 7.4 days
The month with the highest number of rainy days is May (12.7 days).
The month with the least rainy days is January (3.6 days).
Average snowfall in September
Guernsey, WY
- Average snowfall in September: 0.94"
The month with the highest snowfall is April (4.45").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Guernsey, WY
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is February (8.3 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Guernsey, WY
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 10h and 36min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The months with the least sunshine are February and December (Average sunshine: 6h and 36min).
Average sunshine days in September
Guernsey, WY
- Average sunshine days in September: 20.1 days
The month with the most sunshine days is January (21.9 days).
The month with the least sunshine days is April (14.5 days).
Average UV index in September
Guernsey, WY
- Average UV index in September: 5
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, November and December (UV index 2).
Average cloud cover in September
Guernsey, WY
- Average cloud cover in September: 16
The month with the most cloud cover is April (Cloud cover 31).
The months with the least cloud cover are August and September (Cloud cover 16).
Average visibility in September
Guernsey, 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).
