September weather forecastBlackfoot, ID
September
Weather in September
September brings a noticeable change in the weather in Blackfoot, signaling the onset of the fall season. The shift from the warm temperatures of August to slightly cooler September makes its mark. Despite the summer's end, it allows the first traces of snowfall, amounting to about 0.31" (8mm). The transition to fall is actually a beautiful phase in Blackfoot, where leaves change color from green to gold. It's the ideal time for long walks and outdoor picnics while enjoying the crisp fresh air.Temperature
September's arrival correlates with a reduction in the average high-temperature, down from 84.4°F (29.1°C) in August to a still moderately hot 73.8°F (23.2°C). Despite the high peak temperatures, Blackfoot witnesses an average nighttime cooling to a cool 50.2°F (10.1°C) in September.Humidity
In September, the average relative humidity is 40%.Rainfall
In Blackfoot, in September, during 8.5 rainfall days, 0.79" (20mm) of precipitation is typically accumulated. Throughout the year, there are 120.8 rainfall days, and 10.67" (271mm) of precipitation is accumulated.Snowfall
January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.31" (8mm) of snow. Throughout the year, there are 69.9 snowfall days, and 29.37" (746mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:54 am and sunset at 8:03 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 7:11 pm MDT.
Sunshine
In September, the average sunshine is 10h.UV index
In Blackfoot, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: The average daily UV index of 4 in September transforms into the following instructions:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Blackfoot, ID
- Average high temperature in September: 73.8°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is December (28.6°F).
- Average low temperature in September: 50.2°F
The month with the highest average low temperature is August (55.9°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure in September
Blackfoot, ID
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.3"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Blackfoot, ID
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (9.1mph).
The calmest month (with the lowest average wind speed) is January (6.3mph).
Average humidity in September
Blackfoot, ID
- Average humidity in September: 40%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is August (34%).
Average rainfall in September
Blackfoot, ID
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is March (1.22").
The driest month (with the least rainfall) is July (0.39").
Average rainfall days in September
Blackfoot, ID
- Average rainfall days in September: 8.5 days
The month with the highest number of rainy days is March (13.8 days).
The month with the least rainy days is July (7.3 days).
Average snowfall in September
Blackfoot, ID
- Average snowfall in September: 0.31"
The month with the highest snowfall is January (7.83").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Blackfoot, ID
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (16.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Blackfoot, 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 0min).
- Average sunshine in September: 10h and 0min
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
Blackfoot, ID
- Average sunshine days in September: 19.3 days
The month with the most sunshine days is October (19.7 days).
The month with the least sunshine days is February (10.5 days).
Average UV index in September
Blackfoot, ID
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Blackfoot, ID
- Average cloud cover in September: 15
The months with the most cloud cover are January and February (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 11).
Average visibility in September
Blackfoot, 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 month with the lowest visibility is January (4mi).
