September weather forecastAltamont, SD
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Altamont, South Dakota, with an average temperature varying between 52.7°F (11.5°C) and 72.5°F (22.5°C).Temperature
Altamont's September weather shows a modest shift in high-temperatures, falling from August's moderately hot 80.1°F (26.7°C) to a pleasant 72.5°F (22.5°C). Altamont experiences an average low-temperature of 52.7°F (11.5°C) in the month of September.Humidity
The average relative humidity in September in Altamont is 69%.Rainfall
In Altamont, during September, the rain falls for 9.8 days and regularly aggregates up to 1.26" (32mm) of precipitation. In Altamont, during the entire year, the rain falls for 101.9 days and collects up to 14.61" (371mm) of precipitation.Snowfall
In Altamont, snow does not fall in June through September.Daylight
In Altamont, the average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:49 am and sunset at 8:03 pm. On the last day of September, in Altamont, sunrise is at 7:24 am and sunset at 7:08 pm CDT.
Sunshine
In September, the average sunshine in Altamont is 9.1h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: In September, the UV index of 4 transforms into the following advice:
Take precautions - Protection against sunburn is recommended. To guard against the harmful effects of the Sun, minimize exposure during midday. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Altamont, SD
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (20.5°F).
- Average low temperature in September: 52.7°F
The month with the highest average low temperature is July (62.1°F).
The coldest month (with the lowest average low temperature) is January (7.2°F).
Average pressure in September
Altamont, SD
- Average pressure in September: 29.98"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in September
Altamont, SD
- Average wind speed in September: 9.3mph
The windiest month (with the highest average wind speed) is April (10.9mph).
The calmest month (with the lowest average wind speed) is July (8mph).
Average humidity in September
Altamont, SD
- Average humidity in September: 69%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (67%).
Average rainfall in September
Altamont, SD
- Average rainfall in September: 1.26"
The wettest month (with the highest rainfall) is July (2.56").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days in September
Altamont, SD
- Average rainfall days in September: 9.8 days
The month with the highest number of rainy days is June (16.5 days).
The month with the least rainy days is January (1.7 days).
Average snowfall in September
Altamont, SD
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.27").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Altamont, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Altamont, SD
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 9h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in September
Altamont, SD
- Average sunshine days in September: 17.9 days
The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is June (11.3 days).
Average UV index in September
Altamont, 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 and November (UV index 1).
Average cloud cover in September
Altamont, SD
- Average cloud cover in September: 28
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in September
Altamont, SD
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
