September weather forecastHammer, SD
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Hammer, South Dakota, with an average temperature varying between 72°F (22.2°C) and 52°F (11.1°C).Temperature
September brings a minor shift in the average high-temperature, adjusting from a warm 80.4°F (26.9°C) in August to a pleasant 72°F (22.2°C). Throughout September nights, Hammer registers an average low-temperature of 52°F (11.1°C).Humidity
September is the least humid month, with an average relative humidity of 65%.Rainfall
In Hammer, during September, the rain falls for 9.9 days and regularly aggregates up to 1.73" (44mm) of precipitation. Throughout the year, there are 107.9 rainfall days, and 20.63" (524mm) of precipitation is accumulated.Snowfall
In Hammer, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:50 am and sunset at 8:05 pm. On the last day of September, sunrise is at 7:26 am and sunset at 7:09 pm CDT.
Sunshine
The average sunshine in September is 8.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: During September, 4 as the daily maximum UV index converts into the following advice:
Act with care - Obligation to protect against skin and eye damage is highlighted. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Hammer, SD
- Average high temperature in September: 72°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 (19°F).
- Average low temperature in September: 52°F
The month with the highest average low temperature is July (61.7°F).
The coldest month (with the lowest average low temperature) is January (5.4°F).
Average pressure in September
Hammer, SD
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is February (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in September
Hammer, SD
- Average wind speed in September: 9.6mph
The windiest months (with the highest average wind speed) are April and October (10.9mph).
The calmest months (with the lowest average wind speed) are July and August (8.3mph).
Average humidity in September
Hammer, SD
- Average humidity in September: 65%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is September (65%).
Average rainfall in September
Hammer, SD
- Average rainfall in September: 1.73"
The wettest month (with the highest rainfall) is July (3.27").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in September
Hammer, SD
- Average rainfall days in September: 9.9 days
The month with the highest number of rainy days is June (17.6 days).
The month with the least rainy days is February (1.6 days).
Average snowfall in September
Hammer, SD
- Average snowfall in September: 0"
The month with the highest snowfall is December (4.29").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Hammer, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (11.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Hammer, SD
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Hammer, SD
- Average sunshine days in September: 17.7 days
The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is June (10.8 days).
Average UV index in September
Hammer, SD
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Hammer, SD
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are July and August (Cloud cover 25).
Average visibility in September
Hammer, 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).





