September weather forecastWestport, SD
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Westport, South Dakota, with temperature in the range of an average low of 52.9°F (11.6°C) and an average high of 74.3°F (23.5°C).Temperature
The onset of September aligns with a soft reduction in the average high-temperature, gently falling from a warm 83.1°F (28.4°C) in August to a still moderately hot 74.3°F (23.5°C). Nightly temperatures in Westport drop to an average low of 52.9°F (11.6°C) in September.Humidity
The months with the lowest humidity are August and September, with an average relative humidity of 60%.Rainfall
In Westport, in September, it is raining for 8.9 days, with typically 1.26" (32mm) of accumulated precipitation. In Westport, South Dakota, during the entire year, the rain falls for 97.2 days and collects up to 18.35" (466mm) of precipitation.Snowfall
June through September are months without snowfall in Westport.Daylight
In September, the average length of the day in Westport is 12h and 31min.On the first day of the month, sunrise is at 6:56 am and sunset at 8:11 pm. On the last day of September, sunrise is at 7:31 am and sunset at 7:15 pm CDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
In September, the average daily maximum UV index in Westport is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: A typical high UV index of 4 in September suggests the following recommendations:
Exercise prevention - Precautions against solar damage are endorsed. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Westport, SD
- Average high temperature in September: 74.3°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (20.7°F).
- Average low temperature in September: 52.9°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (6.3°F).
Average pressure in September
Westport, SD
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is February (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Westport, SD
- Average wind speed in September: 9.6mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (8.3mph).
Average humidity in September
Westport, SD
- Average humidity in September: 60%
The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are August and September (60%).
Average rainfall in September
Westport, SD
- Average rainfall in September: 1.26"
The wettest month (with the highest rainfall) is June (3.46").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days in September
Westport, SD
- Average rainfall days in September: 8.9 days
The month with the highest number of rainy days is June (15 days).
The month with the least rainy days is February (2 days).
Average snowfall in September
Westport, SD
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.82").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Westport, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Westport, SD
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Westport, SD
- Average sunshine days in September: 18.7 days
The month with the most sunshine days is November (20.9 days).
The month with the least sunshine days is June (12.7 days).
Average UV index in September
Westport, SD
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February and November (UV index 1).
Average cloud cover in September
Westport, SD
- Average cloud cover in September: 26
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are July and August (Cloud cover 23).
Average visibility in September
Westport, 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).
