September weather forecastRoy, UT
September
Weather in September
September in Roy delineates a noticeable reduction in the summer heat, with a significant cooling effect—as temperatures decrease to a modest 72.5°F (22.5°C)—from the preceding summer months. The beginning of fall characterizes this month, with days gradually becoming shorter. Although summer activities gradually wind down, residents and tourists still exploit the warm weather to its fullest extent. This transition denotes a shift from the summer holiday spirit to the more routine, hustling environment of autumn.Temperature
Roy in September undergoes a mild reduction in the average high-temperature, shifting from August's warm 81.9°F (27.7°C) to an agreeable 72.5°F (22.5°C). During the month of September, an average temperature of 52.7°F (11.5°C) is noted during the nights in Roy.Humidity
In September, the average relative humidity is 44%.Rainfall
In September, the rain falls for 7.5 days. Throughout September, 0.98" (25mm) of precipitation is accumulated. Throughout the year, there are 91.6 rainfall days, and 11.06" (281mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows in Roy. Throughout September, in the average 0.2 snowfall days, it receives 0.39" (10mm) of snow. Throughout the year, there are 37.8 snowfall days, and 24.76" (629mm) of snow is accumulated.Daylight
In Roy, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:55 am and sunset at 8:00 pm. On the last day of September, sunrise is at 7:24 am and sunset at 7:11 pm MDT.
Sunshine
In September, the average sunshine is 9.9h.UV index
In Roy, Utah, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.Note: The maximum UV index, 5 during September, leads to the following recommendations:
Undertake protective steps - Preventing sun damage is advised. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Roy, UT
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in September: 52.7°F
The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in September
Roy, UT
- Average pressure in September: 29.95"Hg
The month with the highest atmospheric pressure is January (30.29"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Roy, UT
- Average wind speed in September: 5.8mph
The windiest month (with the highest average wind speed) is April (6.5mph).
The calmest month (with the lowest average wind speed) is January (4.8mph).
Average humidity in September
Roy, UT
- Average humidity in September: 44%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is July (37%).
Average rainfall in September
Roy, UT
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is April (1.26").
The driest month (with the least rainfall) is July (0.43").
Average rainfall days in September
Roy, UT
- Average rainfall days in September: 7.5 days
The month with the highest number of rainy days is May (12.5 days).
The month with the least rainy days is January (4.6 days).
Average snowfall in September
Roy, UT
- Average snowfall in September: 0.39"
The month with the highest snowfall is January (6.89").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Roy, UT
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Roy, UT
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 54min
The months with the most sunshine are June, July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 5h and 36min).
Average sunshine days in September
Roy, UT
- Average sunshine days in September: 18.8 days
The months with the most sunshine days are October and November (21.6 days).
The month with the least sunshine days is April (14.7 days).
Average UV index in September
Roy, UT
- 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
Roy, UT
- Average cloud cover in September: 13
The months with the most cloud cover are January and February (Cloud cover 40).
The month with the least cloud cover is August (Cloud cover 10).
Average visibility in September
Roy, UT
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
