September weather forecastSaint Stephens, WY
September
Weather in September
The first month of the autumn, September, is still a warm month in Saint Stephens, Wyoming, with an average temperature fluctuating between 75.6°F (24.2°C) and 52.9°F (11.6°C).Temperature
Onset of September witnesses a reduction in the average high-temperature, falling from a moderately hot 84.9°F (29.4°C) in August to a still warm 75.6°F (24.2°C). In Saint Stephens, the average temperature during the nights of September marks a significant drop from the daily high, settling at a fresh 52.9°F (11.6°C).Humidity
The average relative humidity in September in Saint Stephens is 35%.Rainfall
In Saint Stephens, in September, during 6 rainfall days, 0.55" (14mm) of precipitation is typically accumulated. In Saint Stephens, during the entire year, the rain falls for 67.3 days and collects up to 6.93" (176mm) of precipitation.Snowfall
January through May, September through December are months with snowfall in Saint Stephens. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.63" (16mm) of snow. In Saint Stephens, during the entire year, snow falls for 42.8 days and aggregates up to 25.47" (647mm) of snow.Daylight
In Saint Stephens, Wyoming, the average length of the day in September is 12h and 29min.On the first day of September in Saint Stephens, sunrise is at 6:39 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:56 pm MDT.
Sunshine
In Saint Stephens, Wyoming, the average sunshine in September is 10.7h.UV index
In Saint Stephens, 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 average individuals.Note: A maximum high daily UV index of 4 during September translates into the following directions:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Saint Stephens, WY
- Average high temperature in September: 75.6°F
The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is December (30.9°F).
- Average low temperature in September: 52.9°F
The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is January (14.5°F).
Average pressure in September
Saint Stephens, WY
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.22"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Saint Stephens, WY
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is June (7.5mph).
The calmest month (with the lowest average wind speed) is January (5.5mph).
Average humidity in September
Saint Stephens, WY
- Average humidity in September: 35%
The month with the highest relative humidity is January (77%).
The months with the lowest relative humidity are July and August (31%).
Average rainfall in September
Saint Stephens, WY
- Average rainfall in September: 0.55"
The wettest month (with the highest rainfall) is May (1.42").
The driest month (with the least rainfall) is January (0.24").
Average rainfall days in September
Saint Stephens, WY
- Average rainfall days in September: 6 days
The month with the highest number of rainy days is May (9.9 days).
The month with the least rainy days is January (2.5 days).
Average snowfall in September
Saint Stephens, WY
- Average snowfall in September: 0.63"
The month with the highest snowfall is April (5.39").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Saint Stephens, WY
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is February (7.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Saint Stephens, WY
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 10h and 42min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 6h and 36min).
Average sunshine days in September
Saint Stephens, WY
- Average sunshine days in September: 20.2 days
The month with the most sunshine days is January (24.5 days).
The month with the least sunshine days is April (15.5 days).
Average UV index in September
Saint Stephens, WY
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Saint Stephens, WY
- Average cloud cover in September: 13
The months with the most cloud cover are February and April (Cloud cover 28).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in September
Saint Stephens, 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).
