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 arrival of September signals a shift in temperature, down from a moderately hot 78.4°F (25.8°C) in August to a pleasant 69.1°F (20.6°C). Donnelly documents a significant temperature variance in September, with the mean nighttime lows settling at a chilly 43.3°F (6.3°C).Humidity
In September, the average relative humidity in Donnelly is 50%.Rainfall
In September, in Donnelly, the rain falls for 7.7 days. Throughout September, 0.79" (20mm) of precipitation is accumulated. In Donnelly, during the entire year, the rain falls for 98.1 days and collects up to 22.64" (575mm) of precipitation.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 0.5 snowfall days, it receives 0.08" (2mm) of snow. Throughout the year, in Donnelly, there are 93.8 snowfall days, and 104.45" (2653mm) of snow is accumulated.Daylight
The average length of the day in September in Donnelly is 12h and 30min.On the first day of September, sunrise is at 7:07 am and sunset at 8:20 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 7:26 pm MDT.
Sunshine
In September, the average sunshine in Donnelly is 9.3h.UV index
In September, the average daily maximum UV index in Donnelly is 3. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: In September, a daily maximum UV index of 3 leads to the following instructions:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Frequently asked questions
What is the average September temperature in Donnelly?
What is the average humidity in September in Donnelly?
How many days does it rain in September in Donnelly?
When does it start snowing in Donnelly?
How many hours of daylight does Donnelly have in September?
What time are sunrise and sunset in September in Donnelly?
How long on average sun shines in September in Donnelly?
What is the UV index reading in September in Donnelly?
Average temperature in September
Donnelly, ID
- Average high temperature in September: 69.1°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is December (28°F).
- Average low temperature in September: 43.3°F
The month with the highest average low temperature is August (50°F).
The coldest month (with the lowest average low temperature) is January (14.7°F).
Average pressure in September
Donnelly, ID
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.24"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Donnelly, ID
- Average wind speed in September: 4.9mph
The windiest months (with the highest average wind speed) are March and April (5.3mph).
The calmest month (with the lowest average wind speed) is January (4.2mph).
Average humidity in September
Donnelly, ID
- Average humidity in September: 50%
The months with the highest relative humidity are January and February (91%).
The month with the lowest relative humidity is August (42%).
Average rainfall in September
Donnelly, ID
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is March (3.31").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in September
Donnelly, ID
- Average rainfall days in September: 7.7 days
The month with the highest number of rainy days is May (14.4 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in September
Donnelly, ID
- Average snowfall in September: 0.08"
The month with the highest snowfall is January (23.07").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Donnelly, ID
- Average snowfall days in September: 0.5 days
The month with the highest number of snowfall days is March (17 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Donnelly, ID
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Donnelly, ID
- Average sunshine days in September: 20.4 days
The month with the most sunshine days is July (23.8 days).
The month with the least sunshine days is March (10.1 days).
Average UV index in September
Donnelly, ID
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February and November (UV index 1).
Average cloud cover in September
Donnelly, ID
- Average cloud cover in September: 17
The month with the most cloud cover is February (Cloud cover 59).
The months with the least cloud cover are July and August (Cloud cover 10).
Average visibility in September
Donnelly, ID
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The month with the lowest visibility is January (3mi).
Donnelly, Idaho, USA
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