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 average high-temperature decreases in September, shifting from a warm 78.4°F (25.8°C) in August to a pleasant 69.1°F (20.6°C). During September, Donnelly perceives a consistent contrast from the daytime highs, with an average low-temperature of 43.3°F (6.3°C).Humidity
In Donnelly, the average relative humidity in September is 50%.Rainfall
In Donnelly, Idaho, during September, the rain falls for 7.7 days and regularly aggregates up to 0.79" (20mm) of precipitation. Throughout the year, there are 98.1 rainfall days, and 22.64" (575mm) 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 0.5 snowfall days, it receives 0.08" (2mm) of snow. Throughout the year, there are 93.8 snowfall days, and 104.45" (2653mm) of snow is accumulated.Daylight
In Donnelly, the average length of the day in September is 12h and 30min.On the first day of September in Donnelly, 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
The average sunshine in September is 9.3h.UV index
The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: In September, the maximum UV index of 3 suggests this advice:
Exercise care. People with light skin might get burns in fewer than 30 minutes. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Donnelly in September?
What is the average humidity in September?
How much does it rain in September?
When does it start snowing?
How many hours of daylight does Donnelly have in September?
When are sunrise and sunset in September?
How long on average sun shines in September in Donnelly?
How high is the UV index 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
Weather forecast for your location
2. Allow the app to use your location