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 onset of September brings a small change in high-temperatures, falling from a warm 83.3°F (28.5°C) in August to a pleasant 72.9°F (22.7°C). Following the sharp contrast to daytime warmth, an average nighttime temperature of 49.3°F (9.6°C) gets registered in Shelley, Idaho, during September.Humidity
In Shelley, the average relative humidity in September is 41%.Rainfall
In Shelley, in September, it is raining for 10.1 days, with typically 1.06" (27mm) of accumulated precipitation. Throughout the year, in Shelley, there are 124.6 rainfall days, and 12.24" (311mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.2" (5mm) of snow. Throughout the year, in Shelley, there are 75.1 snowfall days, and 30.59" (777mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:53 am and sunset at 8:03 pm. On the last day of September, sunrise is at 7:25 am and sunset at 7:10 pm MDT.
Sunshine
The average sunshine in September is 9.9h.UV index
In September, the average daily maximum UV index in Shelley is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Act with care - The need to guard against sun damage is communicated. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Frequently asked questions
What is the average September temperature in Shelley?
What is the average humidity in September in Shelley?
How many days does it rain in September in Shelley?
When does it start snowing in Shelley?
What is the average length of the day in September in Shelley?
When are sunrise and sunset in September in Shelley?
How long on average sun shines in September in Shelley?
What is the UV index intensity in September in Shelley?
Average temperature in September
Shelley, ID
- Average high temperature in September: 72.9°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (27.9°F).
- Average low temperature in September: 49.3°F
The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is January (14.7°F).
Average pressure in September
Shelley, ID
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.3"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Shelley, ID
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (8.9mph).
The calmest month (with the lowest average wind speed) is January (6mph).
Average humidity in September
Shelley, ID
- Average humidity in September: 41%
The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are July and August (36%).
Average rainfall in September
Shelley, ID
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is May (1.57").
The driest month (with the least rainfall) is July (0.51").
Average rainfall days in September
Shelley, ID
- Average rainfall days in September: 10.1 days
The month with the highest number of rainy days is May (15.9 days).
The month with the least rainy days is January (6.1 days).
Average snowfall in September
Shelley, ID
- Average snowfall in September: 0.2"
The month with the highest snowfall is January (7.44").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Shelley, ID
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (16.7 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Shelley, ID
- 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: 9h and 5min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 48min).
Average sunshine days in September
Shelley, ID
- Average sunshine days in September: 17.3 days
The month with the most sunshine days is October (18.9 days).
The month with the least sunshine days is March (10 days).
Average UV index in September
Shelley, ID
- 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 and December (UV index 1).
Average cloud cover in September
Shelley, ID
- Average cloud cover in September: 16
The month with the most cloud cover is February (Cloud cover 51).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in September
Shelley, ID
- 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 and February (4mi).
Shelley, Idaho, USA
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