September weather forecast
Roswell, SD

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Roswell, South Dakota, with temperature in the range of an average high of 76.1°F (24.5°C) and an average low of 55°F (12.8°C).

Temperature

The beginning of September subtly marks a decrease in the average high-temperature, transitioning from a warm 84.4°F (29.1°C) in August to a still moderately hot 76.1°F (24.5°C). During September, the average low-temperature is a cool 55°F (12.8°C).

Humidity

The months with the lowest humidity are September and October, with an average relative humidity of 63%.

Rainfall

In Roswell, during September, the rain falls for 9.2 days and regularly aggregates up to 1.18" (30mm) of precipitation. In Roswell, during the entire year, the rain falls for 93.2 days and collects up to 11.3" (287mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

The average length of the day in September is 12h and 29min.
On the first day of the month, sunrise is at 6:54 am and sunset at 8:06 pm. On the last day of September, sunrise is at 7:28 am and sunset at 7:12 pm CDT.

Sunshine

The average sunshine in September is 8.9h.

UV index

In Roswell, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In September, a daily maximum UV index of 5 leads to the following instructions:
Undertake protective steps - Recommendations to avoid sunburn are issued. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.
Updated: Jul 30, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September?

Roswell in September has an average high-temperature of 76.1°F (24.5°C) and an average low-temperature of 55°F (12.8°C). In August, the average heat index (a.k.a. 'real feel', 'feels like'), which represents the influence of relative humidity on air temperature, is estimated at 89.6°F (32°C).

What is the least humid month?

September and October, with an average relative humidity of 63%, are the least humid months.

What is the average humidity in September?

In Roswell, the average relative humidity in September is 63%.

How many days does it rain in September in Roswell?

In Roswell, in September, during 9.2 rainfall days, 1.18" (30mm) of precipitation is typically accumulated.

When it does not snow?

May through September are months without snowfall.

Does it snow in September?

In Roswell, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September?

In September, the average day length is 12h and 29min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:54 am and sunset at 8:06 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 7:12 pm CDT.

How many hours of sunshine does Roswell have in September?

In September, the average sunshine duration is 8.9h.

How high is the UV index in September?

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Roswell, SD

Average temperature in September - Roswell, SD
  • Average high temperature in September: 76.1°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 (24.4°F).

  • Average low temperature in September: 55°F

The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (10.2°F).

Average pressure in September
Roswell, SD

Average pressure in September - Roswell, 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 (29.85"Hg).

Average wind speed in September
Roswell, SD

Average wind speed in September - Roswell, SD
  • Average wind speed in September: 9.7mph

The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is July (8.6mph).

Average humidity in September
Roswell, SD

Average humidity in September - Roswell, SD
  • Average humidity in September: 63%

The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are September and October (63%).

Average rainfall in September
Roswell, SD

Average rainfall in September - Roswell, SD
  • Average rainfall in September: 1.18"

The wettest month (with the highest rainfall) is May (1.65").
The driest months (with the least rainfall) are February and November (0.28").

Average rainfall days in September
Roswell, SD

Average rainfall days in September - Roswell, SD
  • Average rainfall days in September: 9.2 days

The month with the highest number of rainy days is June (13.6 days).
The month with the least rainy days is February (1.9 days).

Average snowfall in September
Roswell, SD

Average snowfall in September - Roswell, SD
  • Average snowfall in September: 0"

The month with the highest snowfall is February (1.42").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Roswell, SD

Average snowfall days in September - Roswell, SD
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (8.7 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Roswell, SD

Average daylight in September / Average sunshine in September - Roswell, SD
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).

  • Average sunshine in September: 8h and 5min

The month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).

Average sunshine days in September
Roswell, SD

Average sunshine days in September - Roswell, SD
  • Average sunshine days in September: 18.3 days

The month with the most sunshine days is November (23.4 days).
The month with the least sunshine days is June (12.8 days).

Average UV index in September
Roswell, SD

Average UV index in September - Roswell, SD
  • Average UV index in September: 5

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).

Average cloud cover in September
Roswell, SD

Average cloud cover in September - Roswell, SD
  • Average cloud cover in September: 26

The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 22).

Average visibility in September
Roswell, SD

Average visibility in September - Roswell, SD
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Roswell, South Dakota, USA

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