September weather forecastOnaka, SD
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Onaka, South Dakota, with an average temperature ranging between min 54.5°F (12.5°C) and max 74.5°F (23.6°C).Temperature
The start of September comes with a reduction in the average high-temperature, receding from 83.8°F (28.8°C) in August to a still warm 74.5°F (23.6°C). September's average low-temperature reading settles at a fresh 54.5°F (12.5°C).Humidity
The months with the lowest humidity in Onaka are August and September, with an average relative humidity of 56%.Rainfall
In September, the rain falls for 8.5 days. Throughout September, 1.06" (27mm) of precipitation is accumulated. Throughout the year, there are 97.8 rainfall days, and 16.65" (423mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Onaka, South Dakota, the average length of the day in September is 12h and 31min.On the first day of September, sunrise is at 7:00 am and sunset at 8:14 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 7:19 pm CDT.
Sunshine
In Onaka, the average sunshine in September is 8.6h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: The average daily UV index of 4 in September transforms into the following instructions:
Take precautions - Protection against skin and eye damage is obliged. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Onaka, SD
- Average high temperature in September: 74.5°F
The warmest month (with the highest average high temperature) is July (85.8°F).
The month with the lowest average high temperature is January (22.6°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (9.1°F).
Average pressure in September
Onaka, SD
- Average pressure in September: 29.95"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in September
Onaka, SD
- Average wind speed in September: 11.1mph
The windiest month (with the highest average wind speed) is April (11.8mph).
The calmest month (with the lowest average wind speed) is August (9.7mph).
Average humidity in September
Onaka, SD
- Average humidity in September: 56%
The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are August and September (56%).
Average rainfall in September
Onaka, SD
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is June (2.8").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in September
Onaka, SD
- Average rainfall days in September: 8.5 days
The month with the highest number of rainy days is June (14.4 days).
The month with the least rainy days is February (1.9 days).
Average snowfall in September
Onaka, SD
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.04").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Onaka, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Onaka, 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 36min
The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Onaka, SD
- Average sunshine days in September: 19.6 days
The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is June (13.1 days).
Average UV index in September
Onaka, 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, November and December (UV index 1).
Average cloud cover in September
Onaka, SD
- Average cloud cover in September: 25
The month with the most cloud cover is January (Cloud cover 58).
The months with the least cloud cover are July and August (Cloud cover 22).
Average visibility in September
Onaka, 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).
