September weather forecastMountain View, WY
September
Weather in September
Mountain View's climate in September is characterized by a further decrease in temperatures, signaling the onset of fall. Rainfall remains slightly higher compared to summer months, while the first snowfall of 0.43" (11mm) hints at the forthcoming winter. Despite shorter daylight hours, the weather remains pleasant for outdoor activities. The transition into autumn is reflected in the landscapes, as foliage starts turning into hues of gold and brown. September weather, with its temperate climate and scenic charm, enhances Mountain View's appeal to nature enthusiasts.Temperature
September indicates a minor shift in the average high-temperature, from August's moderately hot 76.6°F (24.8°C) to an agreeable 68.5°F (20.3°C). An average temperature of 47.8°F (8.8°C) is recorded during the nights in September.Humidity
The average relative humidity in September is 39%.Rainfall
In Mountain View, during September, the rain falls for 8 days and regularly aggregates up to 0.79" (20mm) of precipitation. In Mountain View, during the entire year, the rain falls for 112.2 days and collects up to 11.57" (294mm) of precipitation.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.7 snowfall days, it receives 0.43" (11mm) of snow. In Mountain View, during the entire year, snow falls for 85.7 days and aggregates up to 41.18" (1046mm) of snow.Daylight
The average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:48 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 7:17 am and sunset at 7:04 pm MDT.
Sunshine
In September, the average sunshine is 10.5h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: The UV index of 4 in September translates into these instructions:
Make use of precautions - Shielding skin and eyes from injury is a requirement. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mountain View, WY
- Average high temperature in September: 68.5°F
The warmest month (with the highest average high temperature) is July (78.4°F).
The month with the lowest average high temperature is December (26.6°F).
- Average low temperature in September: 47.8°F
The month with the highest average low temperature is July (55.6°F).
The coldest month (with the lowest average low temperature) is January (12.2°F).
Average pressure in September
Mountain View, 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 (29.88"Hg).
Average wind speed in September
Mountain View, WY
- Average wind speed in September: 8.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is July (7.6mph).
Average humidity in September
Mountain View, WY
- Average humidity in September: 39%
The months with the highest relative humidity are January and February (82%).
The months with the lowest relative humidity are July and August (36%).
Average rainfall in September
Mountain View, WY
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is May (2.01").
The driest months (with the least rainfall) are January and July (0.63").
Average rainfall days in September
Mountain View, WY
- Average rainfall days in September: 8 days
The month with the highest number of rainy days is May (16.1 days).
The month with the least rainy days is November (6 days).
Average snowfall in September
Mountain View, WY
- Average snowfall in September: 0.43"
The month with the highest snowfall is March (8.78").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Mountain View, WY
- Average snowfall days in September: 0.7 days
The month with the highest number of snowfall days is March (15.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Mountain View, 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 18min).
- Average sunshine in September: 10h and 30min
The months with the most sunshine are July and August (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 6h and 24min).
Average sunshine days in September
Mountain View, WY
- Average sunshine days in September: 18.8 days
The month with the most sunshine days is October (19.2 days).
The month with the least sunshine days is April (9.4 days).
Average UV index in September
Mountain View, WY
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).
Average cloud cover in September
Mountain View, WY
- Average cloud cover in September: 13
The month with the most cloud cover is February (Cloud cover 36).
The month with the least cloud cover is August (Cloud cover 12).
Average visibility in September
Mountain View, WY
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
