September weather forecastRockham, SD
September
Weather in September
The first month of the autumn, September, is still a warm month in Rockham, South Dakota, with an average temperature fluctuating between 75.9°F (24.4°C) and 54.5°F (12.5°C).Temperature
Rockham observes a small decrease in the average high-temperature with the arrival of September, falling from August's warm 84.4°F (29.1°C) to a still moderately hot 75.9°F (24.4°C). During the month of September, Rockham's nighttime temperature lowers to an average of 54.5°F (12.5°C).Humidity
September is the least humid month, with an average relative humidity of 60%.Rainfall
In Rockham, in September, during 9.3 rainfall days, 1.1" (28mm) of precipitation is typically accumulated. Throughout the year, there are 97.6 rainfall days, and 17.83" (453mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:58 am and sunset at 8:11 pm. On the last day of September, sunrise is at 7:33 am and sunset at 7:17 pm CDT.
Sunshine
In Rockham, South Dakota, the average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the average person.Note: A maximum daily UV index of 4 during September morphs into the following directions:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rockham, SD
- Average high temperature in September: 75.9°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (22.5°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (7.9°F).
Average pressure in September
Rockham, SD
- Average pressure in September: 29.96"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
Rockham, SD
- Average wind speed in September: 9.7mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (8.5mph).
Average humidity in September
Rockham, SD
- Average humidity in September: 60%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is September (60%).
Average rainfall in September
Rockham, SD
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is June (3.03").
The driest month (with the least rainfall) is January (0.51").
Average rainfall days in September
Rockham, SD
- Average rainfall days in September: 9.3 days
The month with the highest number of rainy days is June (15.1 days).
The month with the least rainy days is February (1.9 days).
Average snowfall in September
Rockham, SD
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.09").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Rockham, SD
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Rockham, 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: 8h and 48min
The month with the most sunshine is July (Average sunshine: 11h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Rockham, SD
- Average sunshine days in September: 18.4 days
The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is June (12.2 days).
Average UV index in September
Rockham, 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 and February (UV index 1).
Average cloud cover in September
Rockham, SD
- Average cloud cover in September: 25
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is July (Cloud cover 22).
Average visibility in September
Rockham, 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).
