September weather forecastDenby, SD
September
Weather in September
The first month of the autumn, September, is still a warm month in Denby, South Dakota, with an average temperature fluctuating between 77°F (25°C) and 55.9°F (13.3°C).Temperature
The arrival of September suggests a slight decrease in the average high-temperature, moving from a moderately hot 85.6°F (29.8°C) in August to a still warm 77°F (25°C). Throughout the September nights, Denby encounters a low-temperature of 55.9°F (13.3°C).Humidity
The average relative humidity in September is 49%.Rainfall
In Denby, during September, the rain falls for 6.1 days and regularly aggregates up to 1.02" (26mm) of precipitation. Throughout the year, there are 86.7 rainfall days, and 13.66" (347mm) 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 0.04" (1mm) of snow. Throughout the year, there are 47.4 snowfall days, and 22.72" (577mm) of snow is accumulated.Daylight
In September, the average length of the day is 12h and 29min.On the first day of the month, sunrise is at 6:14 am and sunset at 7:23 pm. On the last day of September, sunrise is at 6:46 am and sunset at 6:31 pm MDT.
Sunshine
The average sunshine in September is 10.2h.UV index
In Denby, 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 ordinary person.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Make use of precautions - It is urged to ward off sun damage. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Denby, SD
- Average high temperature in September: 77°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is December (32.4°F).
- Average low temperature in September: 55.9°F
The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (18.1°F).
Average pressure in September
Denby, SD
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Denby, SD
- Average wind speed in September: 11.2mph
The windiest month (with the highest average wind speed) is April (12.2mph).
The calmest month (with the lowest average wind speed) is August (10.2mph).
Average humidity in September
Denby, SD
- Average humidity in September: 49%
The month with the highest relative humidity is January (80%).
The month with the lowest relative humidity is August (48%).
Average rainfall in September
Denby, SD
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is May (2.13").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in September
Denby, SD
- Average rainfall days in September: 6.1 days
The month with the highest number of rainy days is May (13.1 days).
The months with the least rainy days are February and December (2.5 days).
Average snowfall in September
Denby, SD
- Average snowfall in September: 0.04"
The month with the highest snowfall is February (4.02").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Denby, SD
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (11.5 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Denby, SD
- 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: 10h and 12min
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 12min).
Average sunshine days in September
Denby, SD
- Average sunshine days in September: 22.8 days
The month with the most sunshine days is September (22.8 days).
The month with the least sunshine days is April (13.2 days).
Average UV index in September
Denby, SD
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Denby, SD
- Average cloud cover in September: 19
The month with the most cloud cover is February (Cloud cover 44).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in September
Denby, 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).
