Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The start of September involves a subtle temperature drop, shifting from a warm 73.9°F (23.3°C) in August to an enjoyable 65.8°F (18.8°C). Grass Creek, during September nights, observes an average temperature of 45.5°F (7.5°C).Humidity
In September, the average relative humidity is 46%.Rainfall
In Grass Creek, during September, the rain falls for 8.9 days and regularly aggregates up to 0.94" (24mm) of precipitation. Throughout the year, there are 93.8 rainfall days, and 12.05" (306mm) of precipitation is accumulated.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.8 snowfall days, it receives 0.75" (19mm) of snow. In Grass Creek, during the entire year, snow falls for 55.8 days and aggregates up to 30.31" (770mm) of snow.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:38 am and sunset at 7:49 pm. On the last day of September, sunrise is at 7:12 am and sunset at 6:56 pm MDT.
Sunshine
The average sunshine in September is 10.4h.UV index
The average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: The average daily UV index of 3 in September transforms into the following instructions:
Guard yourself - Precautionary measures against sun damage are advocated. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. 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
What is the average September temperature in Grass Creek?
What is the average humidity in September?
How many days does it rain in September?
When does it start snowing?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Grass Creek, WY
- Average high temperature in September: 65.8°F
The warmest month (with the highest average high temperature) is July (76.1°F).
The month with the lowest average high temperature is December (27.3°F).
- Average low temperature in September: 45.5°F
The month with the highest average low temperature is July (53.8°F).
The coldest month (with the lowest average low temperature) is December (11.8°F).
Average pressure in September
Grass Creek, WY
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Grass Creek, WY
- Average wind speed in September: 6.1mph
The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).
Average humidity in September
Grass Creek, WY
- Average humidity in September: 46%
The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is July (43%).
Average rainfall in September
Grass Creek, WY
- Average rainfall in September: 0.94"
The wettest month (with the highest rainfall) is May (2.48").
The driest month (with the least rainfall) is January (0.2").
Average rainfall days in September
Grass Creek, WY
- Average rainfall days in September: 8.9 days
The month with the highest number of rainy days is May (16.9 days).
The month with the least rainy days is January (1.6 days).
Average snowfall in September
Grass Creek, WY
- Average snowfall in September: 0.75"
The month with the highest snowfall is April (6.3").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Grass Creek, WY
- Average snowfall days in September: 0.8 days
The month with the highest number of snowfall days is April (9.4 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Grass Creek, WY
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 10h and 2min
The month with the most sunshine is July (Average sunshine: 11h and 42min).
The month with the least sunshine is February (Average sunshine: 6h and 24min).
Average sunshine days in September
Grass Creek, WY
- Average sunshine days in September: 18.7 days
The month with the most sunshine days is January (25 days).
The month with the least sunshine days is May (10.2 days).
Average UV index in September
Grass Creek, WY
- Average UV index in September: 3
The months with the highest UV index are June and July (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
Grass Creek, WY
- Average cloud cover in September: 17
The month with the most cloud cover is April (Cloud cover 35).
The months with the least cloud cover are July and September (Cloud cover 17).
Average visibility in September
Grass Creek, 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).
Grass Creek, Wyoming, USA
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