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
September's onset corresponds with a shift in the average high-temperature, moving from a warm 75.7°F (24.3°C) in August to a comfortable 65.8°F (18.8°C). Eighteenmile, amidst the high September temperatures, experiences a substantial shift to an average nighttime low of 40.1°F (4.5°C).Humidity
The average relative humidity in September is 53%.Rainfall
In Eighteenmile, Idaho, in September, during 7.9 rainfall days, 1.14" (29mm) of precipitation is typically accumulated. Throughout the year, there are 106.1 rainfall days, and 20.83" (529mm) of precipitation is accumulated.Snowfall
January through July, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 1.2 snowfall days, it receives 1.69" (43mm) of snow. Throughout the year, there are 138.1 snowfall days, and 107.64" (2734mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 30min.On the first day of the month, sunrise is at 6:51 am and sunset at 8:03 pm. On the last day of September, sunrise is at 7:25 am and sunset at 7:09 pm MDT.
Sunshine
In Eighteenmile, Idaho, the average sunshine in September is 9.9h.UV index
In September, the average daily maximum UV index is 3. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 3 suggests these recommendations:
Adopt protective measures - It is advised to guard against sun damage. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Notice! The UV radiation of the Sun can be intensified nearly twofold due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September in Eighteenmile?
How many days does it rain in September?
When does it start to snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Eighteenmile, ID
- Average high temperature in September: 65.8°F
The warmest month (with the highest average high temperature) is July (77.4°F).
The month with the lowest average high temperature is December (22.3°F).
- Average low temperature in September: 40.1°F
The month with the highest average low temperature is August (46.6°F).
The coldest months (with the lowest average low temperature) are January and December (6.8°F).
Average pressure in September
Eighteenmile, ID
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.26"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Eighteenmile, ID
- Average wind speed in September: 5.5mph
The windiest month (with the highest average wind speed) is June (6.3mph).
The calmest month (with the lowest average wind speed) is January (4.4mph).
Average humidity in September
Eighteenmile, ID
- Average humidity in September: 53%
The months with the highest relative humidity are January and February (94%).
The month with the lowest relative humidity is August (47%).
Average rainfall in September
Eighteenmile, ID
- Average rainfall in September: 1.14"
The wettest month (with the highest rainfall) is February (2.64").
The driest month (with the least rainfall) is July (0.47").
Average rainfall days in September
Eighteenmile, ID
- Average rainfall days in September: 7.9 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is January (3.8 days).
Average snowfall in September
Eighteenmile, ID
- Average snowfall in September: 1.69"
The month with the highest snowfall is January (19.84").
The month with the least snowfall is August (0").
Average snowfall days in September
Eighteenmile, ID
- Average snowfall days in September: 1.2 days
The month with the highest number of snowfall days is December (23 days).
The month with the least snowfall days is August (0 days).
Average daylight in September /
Average sunshine in September
Eighteenmile, 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 5min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Eighteenmile, ID
- Average sunshine days in September: 19.3 days
The month with the most sunshine days is July (21.2 days).
The month with the least sunshine days is February (5.9 days).
Average UV index in September
Eighteenmile, ID
- 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, November and December (UV index 1).
Average cloud cover in September
Eighteenmile, ID
- Average cloud cover in September: 19
The month with the most cloud cover is February (Cloud cover 67).
The month with the least cloud cover is July (Cloud cover 13).
Average visibility in September
Eighteenmile, ID
- Average visibility in September: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February and December (3mi).
Eighteenmile, Idaho, USA
Weather forecast for your location
2. Allow the app to use your location