September weather forecastDevils Tower, WY
September
Weather in September
As summer retreats, September in Devils Tower dawns with the onset of mild autumn. Following the more heated August, a noticeable descent in temperatures paints a picture of colder nights and fresher days. A steep drop in rainfall levels to 0.91" (23mm) marks the driest month of the year, keeping the skies predominantly clear and blue. Remember to carry a light sweater as the autumn chill starts to fill in the air, especially during the evening. Looking forward to October, brace for the drastic changes in weather conditions that bring in the winter season.Temperature
September's arrival in Devils Tower comes with a decrease in the average high-temperature, moving from a warm 81.9°F (27.7°C) in August to a pleasant 72.9°F (22.7°C). Throughout September, an average low-temperature of 51.8°F (11°C) is experienced.Humidity
August and September, with an average relative humidity of 49%, are the least humid months.Rainfall
In Devils Tower, Wyoming, during September, the rain falls for 7.6 days and regularly aggregates up to 0.91" (23mm) of precipitation. In Devils Tower, during the entire year, the rain falls for 99.6 days and collects up to 15.71" (399mm) 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 0.2 snowfall days, it receives 0.43" (11mm) of snow. In Devils Tower, during the entire year, snow falls for 57 days and aggregates up to 36.46" (926mm) of snow.Daylight
The average length of the day in September is 12h and 30min.On the first day of the month, sunrise is at 6:22 am and sunset at 7:34 pm. On the last day of September, sunrise is at 6:56 am and sunset at 6:40 pm MDT.
Sunshine
In September, the average sunshine is 10.4h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Ensure safety - Sun damage prevention is strongly urged. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Beware! Reflection from snow can magnify 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
Devils Tower, WY
- Average high temperature in September: 72.9°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is December (30.9°F).
- Average low temperature in September: 51.8°F
The month with the highest average low temperature is July (61°F).
The coldest month (with the lowest average low temperature) is February (16.2°F).
Average pressure in September
Devils Tower, WY
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Devils Tower, WY
- Average wind speed in September: 8.8mph
The windiest month (with the highest average wind speed) is January (10.2mph).
The calmest month (with the lowest average wind speed) is August (8mph).
Average humidity in September
Devils Tower, WY
- Average humidity in September: 49%
The month with the highest relative humidity is January (79%).
The months with the lowest relative humidity are August and September (49%).
Average rainfall in September
Devils Tower, WY
- Average rainfall in September: 0.91"
The wettest month (with the highest rainfall) is May (2.32").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days in September
Devils Tower, WY
- Average rainfall days in September: 7.6 days
The month with the highest number of rainy days is May (15.6 days).
The month with the least rainy days is February (2.9 days).
Average snowfall in September
Devils Tower, WY
- Average snowfall in September: 0.43"
The month with the highest snowfall is April (7.36").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Devils Tower, WY
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is February (11.2 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Devils Tower, 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 24min
The month with the most sunshine is August (Average sunshine: 11h and 42min).
The months with the least sunshine are February and December (Average sunshine: 5h and 42min).
Average sunshine days in September
Devils Tower, WY
- Average sunshine days in September: 20.3 days
The months with the most sunshine days are September and November (20.3 days).
The month with the least sunshine days is May (12.7 days).
Average UV index in September
Devils Tower, WY
- 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, April, November and December (UV index 2).
Average cloud cover in September
Devils Tower, WY
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 41).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in September
Devils Tower, 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).
