September weather forecastBox Elder, SD
September
Weather in September
As September arrives, Box Elder starts to experience a significant reduction in temperature, affecting the sunny, summer spirit. The city enters the transitional phase towards autumn with shorter days and a remarkable drop in the highest temperatures, marking the end of hot summer days. The level of rainfall increases slightly to 0.94" (24mm), adding a cooling effect to the environment. Colors start to change, forming a spectacular mosaic of autumn shades that precede the colder months. By the end of September, Box Elder is adorned with the typical autumn aura, ready to embrace the swift transition into full-fledged fall.Temperature
Box Elder's progression into September involves a gentle drop in the average high-temperature, from 82.8°F (28.2°C) in August to a still warm 73.9°F (23.3°C). Box Elder records an average low-temperature of 54°F (12.2°C) throughout the month of September.Humidity
August and September, with an average relative humidity of 50%, are the least humid months.Rainfall
In Box Elder, in September, it is raining for 7.8 days, with typically 0.94" (24mm) of accumulated precipitation. In Box Elder, during the entire year, the rain falls for 118.8 days and collects up to 15.39" (391mm) of precipitation.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 0.12" (3mm) of snow. In Box Elder, during the entire year, snow falls for 50.4 days and aggregates up to 24.41" (620mm) of snow.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:16 am and sunset at 7:27 pm. On the last day of September, in Box Elder, sunrise is at 6:49 am and sunset at 6:34 pm MDT.
Sunshine
In September, the average sunshine is 10.4h.UV index
In Box Elder, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: In September, a regular UV index of 4 translates into these guidelines:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. To protect against the Sun's most potent rays, avoid direct exposure around midday. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Box Elder, SD
- Average high temperature in September: 73.9°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is December (32.5°F).
- Average low temperature in September: 54°F
The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is February (17.8°F).
Average pressure in September
Box Elder, SD
- Average pressure in September: 29.93"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Box Elder, SD
- Average wind speed in September: 9.1mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is August (8.2mph).
Average humidity in September
Box Elder, SD
- Average humidity in September: 50%
The month with the highest relative humidity is January (77%).
The months with the lowest relative humidity are August and September (50%).
Average rainfall in September
Box Elder, SD
- Average rainfall in September: 0.94"
The wettest month (with the highest rainfall) is May (2.28").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days in September
Box Elder, SD
- Average rainfall days in September: 7.8 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is December (4.8 days).
Average snowfall in September
Box Elder, SD
- Average snowfall in September: 0.12"
The month with the highest snowfall is April (5.43").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Box Elder, SD
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (10.5 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Box Elder, SD
- 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: 8h and 54min).
- Average sunshine in September: 10h and 24min
The month with the most sunshine is August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 54min).
Average sunshine days in September
Box Elder, SD
- Average sunshine days in September: 19.9 days
The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is May (11 days).
Average UV index in September
Box Elder, SD
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Box Elder, SD
- Average cloud cover in September: 18
The months with the most cloud cover are February and April (Cloud cover 38).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in September
Box Elder, SD
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
