September weather forecastTwin Forks, ID
September
Weather in September
September, the first month of the autumn in Twin Forks, is still a comfortable month, with an average temperature fluctuating between 66.9°F (19.4°C) and 42.3°F (5.7°C).Temperature
Welcoming September, Twin Forks observes a shift in the average high-temperature, falling from August's warm 76.1°F (24.5°C) to an enjoyable 66.9°F (19.4°C). A noticeable temperature swing characterizes Twin Forks's September nights, dipping to an average of 42.3°F (5.7°C).Humidity
In Twin Forks, the average relative humidity in September is 52%.Rainfall
In Twin Forks, in September, during 9.5 rainfall days, 1.38" (35mm) of precipitation is typically accumulated. Throughout the year, there are 110.1 rainfall days, and 23.35" (593mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows in Twin Forks. Throughout September, in the average 1 snowfall days, it receives 1.06" (27mm) of snow. In Twin Forks, Idaho, during the entire year, snow falls for 125.3 days and aggregates up to 120.47" (3060mm) of snow.Daylight
In Twin Forks, the average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:49 am and sunset at 7:59 pm. On the last day of September, sunrise is at 7:22 am and sunset at 7:06 pm MDT.
Sunshine
In Twin Forks, the average sunshine in September is 10.1h.UV index
In Twin Forks, the average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: In September, an average UV index of 3 transforms into the following instructions:
Make use of precautions - It is urged to ward off sun damage. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Twin Forks, ID
- Average high temperature in September: 66.9°F
The warmest month (with the highest average high temperature) is July (77.2°F).
The month with the lowest average high temperature is December (23.9°F).
- Average low temperature in September: 42.3°F
The month with the highest average low temperature is July (48.7°F).
The coldest month (with the lowest average low temperature) is January (9.1°F).
Average pressure in September
Twin Forks, ID
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.27"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Twin Forks, ID
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is June (6.3mph).
The calmest months (with the lowest average wind speed) are January and December (4.6mph).
Average humidity in September
Twin Forks, ID
- Average humidity in September: 52%
The month with the highest relative humidity is February (93%).
The month with the lowest relative humidity is August (45%).
Average rainfall in September
Twin Forks, ID
- Average rainfall in September: 1.38"
The wettest month (with the highest rainfall) is February (2.91").
The driest month (with the least rainfall) is July (0.71").
Average rainfall days in September
Twin Forks, ID
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is May (16.1 days).
The month with the least rainy days is January (4.5 days).
Average snowfall in September
Twin Forks, ID
- Average snowfall in September: 1.06"
The month with the highest snowfall is January (24.06").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Twin Forks, ID
- Average snowfall days in September: 1 days
The month with the highest number of snowfall days is December (21.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Twin Forks, ID
- Average daylight in September: 12h and 30min
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: 10h and 6min
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 0min).
Average sunshine days in September
Twin Forks, ID
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is July (20.6 days).
The month with the least sunshine days is February (7.3 days).
Average UV index in September
Twin Forks, ID
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, March and December (UV index 1).
Average cloud cover in September
Twin Forks, ID
- Average cloud cover in September: 18
The month with the most cloud cover is February (Cloud cover 65).
The months with the least cloud cover are July and August (Cloud cover 13).
Average visibility in September
Twin Forks, 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 and February (3mi).





