September weather forecastAmerican Falls, ID
September
Weather in September
September in American Falls brings a gradual transition towards cooler autumn weather. A notable dip in temperatures underscores the shift away from the summer season. The increased cloudiness reflects the slowly dipping temperature levels. Slight variations can be observed in other climatological parameters, including a slight increase in wind speed. Favorably, the rainfall averages none too high, holding at a steady 0.75" (19mm) for the month.Temperature
American Falls experiences a temperature shift at the start of September, with average high-temperatures adjusting from 84.4°F (29.1°C) in August to a still moderately hot 73.9°F (23.3°C). During September, American Falls's temperature records a considerable difference from its daily highs to an average low of 51.8°F (11°C).Humidity
In September, the average relative humidity in American Falls is 38%.Rainfall
In September, the rain falls for 8.2 days. Throughout September, 0.75" (19mm) of precipitation is accumulated. Throughout the year, there are 108.7 rainfall days, and 10.47" (266mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows in American Falls. Throughout September, in the average 0.2 snowfall days, it receives 0.39" (10mm) of snow. Throughout the year, there are 57.1 snowfall days, and 25.2" (640mm) of snow is accumulated.Daylight
The average length of the day in September in American Falls, Idaho, is 12h and 28min.On the first day of the month, sunrise is at 6:57 am and sunset at 8:05 pm. On the last day of September, sunrise is at 7:28 am and sunset at 7:13 pm MDT.
Sunshine
In American Falls, the average sunshine in September is 9.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: The average daily UV index of 4 in September transforms into the following instructions:
Undertake protective steps - Preventing sun damage is advised. It's recommended to limit sun exposure when its radiation is at its peak during midday. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. 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
American Falls, ID
- Average high temperature in September: 73.9°F
The warmest month (with the highest average high temperature) is July (85.8°F).
The month with the lowest average high temperature is December (29.3°F).
- Average low temperature in September: 51.8°F
The month with the highest average low temperature is August (58.5°F).
The coldest months (with the lowest average low temperature) are January and December (18°F).
Average pressure in September
American Falls, ID
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.3"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
American Falls, ID
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (9.6mph).
The calmest months (with the lowest average wind speed) are January and December (7mph).
Average humidity in September
American Falls, ID
- Average humidity in September: 38%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is August (32%).
Average rainfall in September
American Falls, ID
- Average rainfall in September: 0.75"
The wettest month (with the highest rainfall) is March (1.18").
The driest month (with the least rainfall) is July (0.59").
Average rainfall days in September
American Falls, ID
- Average rainfall days in September: 8.2 days
The month with the highest number of rainy days is March (12.5 days).
The month with the least rainy days is January (6.4 days).
Average snowfall in September
American Falls, ID
- Average snowfall in September: 0.39"
The month with the highest snowfall is January (7.2").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
American Falls, ID
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (13.7 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
American Falls, ID
- 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: 9h and 48min
The months with the most sunshine are June and July (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 5h and 6min).
Average sunshine days in September
American Falls, ID
- Average sunshine days in September: 19.3 days
The month with the most sunshine days is October (20.3 days).
The month with the least sunshine days is February (12.4 days).
Average UV index in September
American Falls, ID
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
American Falls, ID
- Average cloud cover in September: 15
The months with the most cloud cover are February and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in September
American Falls, 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, February and December (5mi).
