September weather forecastRock Springs, WY
September
Weather in September
September in Rock Springs heralds the onset of autumn, with a decline in temperature from 70.3°F (21.3°C) to 51.3°F (10.7°C). The city relieves the summer heat and welcomes comfortably warm weather with a rainfall of 0.63" (16mm). September brings forth a dramatic transition in the city's foliage, showcasing a spectacular blend of greens, yellows, and reds. The change in the season imparts a fresh feel in the air, making it an excellent time for traveling and recreational activities.Temperature
As August shifts into September, a slight alteration in temperatures is observed, with average highs reducing from a warm 79.3°F (26.3°C) to an agreeable 70.3°F (21.3°C). Throughout the nights in September, Rock Springs experiences an average low-temperature of 51.3°F (10.7°C).Humidity
The average relative humidity in September in Rock Springs, Wyoming, is 36%.Rainfall
In Rock Springs, during September, the rain falls for 7.2 days and regularly aggregates up to 0.63" (16mm) of precipitation. In Rock Springs, Wyoming, during the entire year, the rain falls for 93.5 days and collects up to 10.31" (262mm) of precipitation.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows in Rock Springs. Throughout September, in the average 0.2 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, in Rock Springs, Wyoming, there are 75.5 snowfall days, and 30.16" (766mm) of snow is accumulated.Daylight
In Rock Springs, Wyoming, the average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:43 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 6:59 pm MDT.
Sunshine
In Rock Springs, the average sunshine in September is 10.7h.UV index
In Rock Springs, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the average person.Note: An average UV index of 4 in September transforms into this advice:
Exercise care. People with light skin might get burns in fewer than 30 minutes. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rock Springs, WY
- Average high temperature in September: 70.3°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is December (25.7°F).
- Average low temperature in September: 51.3°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 (10.8°F).
Average pressure in September
Rock Springs, WY
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.28"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Rock Springs, WY
- Average wind speed in September: 9.4mph
The windiest month (with the highest average wind speed) is April (12.2mph).
The calmest month (with the lowest average wind speed) is August (8.7mph).
Average humidity in September
Rock Springs, WY
- Average humidity in September: 36%
The month with the highest relative humidity is January (84%).
The months with the lowest relative humidity are July and August (31%).
Average rainfall in September
Rock Springs, WY
- Average rainfall in September: 0.63"
The wettest month (with the highest rainfall) is May (1.5").
The driest month (with the least rainfall) is July (0.47").
Average rainfall days in September
Rock Springs, WY
- Average rainfall days in September: 7.2 days
The month with the highest number of rainy days is May (13.8 days).
The month with the least rainy days is December (4.7 days).
Average snowfall in September
Rock Springs, WY
- Average snowfall in September: 0.04"
The month with the highest snowfall is March (6.14").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Rock Springs, WY
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (13.5 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Rock Springs, WY
- 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 12min).
- Average sunshine in September: 10h and 42min
The months with the most sunshine are July and August (Average sunshine: 11h and 48min).
The months with the least sunshine are January and December (Average sunshine: 5h and 54min).
Average sunshine days in September
Rock Springs, WY
- Average sunshine days in September: 19.8 days
The month with the most sunshine days is September (19.8 days).
The month with the least sunshine days is April (11.5 days).
Average UV index in September
Rock Springs, 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, March, April, October, November and December (UV index 2).
Average cloud cover in September
Rock Springs, WY
- Average cloud cover in September: 14
The month with the most cloud cover is February (Cloud cover 43).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in September
Rock Springs, WY
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).
