Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The onset of September aligns with a soft reduction in the average high-temperature, gently falling from a moderately hot 80.1°F (26.7°C) in August to a pleasant 71.6°F (22°C). Castlewood usually reports an average low-temperature of 51.3°F (10.7°C) during the month of September.Humidity
The months with the lowest humidity are September and October, with an average relative humidity of 68%.Rainfall
In September, the rain falls for 10.4 days. Throughout September, 1.57" (40mm) of precipitation is accumulated. Throughout the year, there are 112.3 rainfall days, and 18.78" (477mm) of precipitation is accumulated.Snowfall
In Castlewood, snow does not fall in June through September.Daylight
The average length of the day in September in Castlewood is 12h and 30min.On the first day of the month, sunrise is at 6:51 am and sunset at 8:04 pm. On the last day of September, sunrise is at 7:25 am and sunset at 7:09 pm CDT.
Sunshine
In September, the average sunshine in Castlewood is 8.8h.UV index
In Castlewood, South Dakota, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: A typical high UV index of 4 in September suggests the following recommendations:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Consider carefully! The reflective quality of snow can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the least humid month?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Castlewood have in September?
How high is the UV index in September?
Average temperature in September
Castlewood, SD
- Average high temperature in September: 71.6°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (19.4°F).
- Average low temperature in September: 51.3°F
The month with the highest average low temperature is July (60.8°F).
The coldest month (with the lowest average low temperature) is January (5.5°F).
Average pressure in September
Castlewood, SD
- Average pressure in September: 29.97"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Castlewood, SD
- Average wind speed in September: 10mph
The windiest month (with the highest average wind speed) is April (11.6mph).
The calmest month (with the lowest average wind speed) is July (8.5mph).
Average humidity in September
Castlewood, SD
- Average humidity in September: 68%
The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are September and October (68%).
Average rainfall in September
Castlewood, SD
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is June (3.19").
The driest months (with the least rainfall) are January and February (0.59").
Average rainfall days in September
Castlewood, SD
- Average rainfall days in September: 10.4 days
The month with the highest number of rainy days is June (17.2 days).
The month with the least rainy days is February (2.7 days).
Average snowfall in September
Castlewood, SD
- Average snowfall in September: 0"
The months with the highest snowfall are January and December (3.74").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Castlewood, SD
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (14.4 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Castlewood, SD
- Average daylight in September: 12h and 3min
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 5min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Castlewood, SD
- Average sunshine days in September: 18.2 days
The month with the most sunshine days is October (19.1 days).
The month with the least sunshine days is June (10.3 days).
Average UV index in September
Castlewood, 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 December (UV index 1).
Average cloud cover in September
Castlewood, SD
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Castlewood, 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).
Castlewood, South Dakota, USA
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