September weather forecast
Marion, SD

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Weather in September

The first month of the autumn, September, is still a warm month in Marion, South Dakota, with an average temperature varying between 54°F (12.2°C) and 74.7°F (23.7°C).

Temperature

The shift from August to September includes a minor decrease in the average high-temperature, lightly dropping from a warm 81.7°F (27.6°C) to a still moderately hot 74.7°F (23.7°C). An average low-temperature of 54°F (12.2°C) is observed during September nights.

Humidity

In Marion, the average relative humidity in September is 70%.

Rainfall

In Marion, during September, the rain falls for 10.5 days and regularly aggregates up to 1.61" (41mm) of precipitation. Throughout the year, in Marion, there are 111.7 rainfall days, and 17.76" (451mm) of precipitation is accumulated.

Snowfall

June 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 6:53 am and sunset at 8:03 pm. On the last day of September, sunrise is at 7:26 am and sunset at 7:11 pm CDT.

Sunshine

The average sunshine in September is 8.8h.

UV index

In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index of 4 during September translates into the following directions:
Prioritize safety - Suggestions to prevent sun damage are offered. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Enhance your sun protection with tightly woven, yet airy clothing.
Updated: Aug 24, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Marion in September?

In September, the average high-temperature and low-temperature are 74.7°F (23.7°C) and 54°F (12.2°C) respectively. The average heat index (a.k.a. 'feels like', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, in August is computed to be 86°F (30°C).

What is the average humidity in September?

In September, the average relative humidity is 70%.

How many days does it rain in September?

In Marion, during September, the rain falls for 10.5 days and regularly aggregates up to 1.61" (41mm) of precipitation.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

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

What is the average length of the day in September?

The average day length in September is 12h and 29min.

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:53 am and sunset at 8:03 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 7:11 pm CDT.

How long on average sun shines in September?

In September, the average sunshine duration is 8.8h.

How high is the UV index in September?

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium health risk from exposure to the Sun's UV radiation.
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
Marion, SD

Average temperature in September - Marion, SD
  • Average high temperature in September: 74.7°F

The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (24.3°F).

  • Average low temperature in September: 54°F

The month with the highest average low temperature is July (63.7°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).

Average pressure in September
Marion, SD

Average pressure in September - Marion, SD
  • Average pressure in September: 29.98"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).

Average wind speed in September
Marion, SD

Average wind speed in September - Marion, SD
  • Average wind speed in September: 9.3mph

The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.9mph).

Average humidity in September
Marion, SD

Average humidity in September - Marion, SD
  • Average humidity in September: 70%

The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (66%).

Average rainfall in September
Marion, SD

Average rainfall in September - Marion, SD
  • Average rainfall in September: 1.61"

The wettest month (with the highest rainfall) is June (2.91").
The driest months (with the least rainfall) are January, February and November (0.47").

Average rainfall days in September
Marion, SD

Average rainfall days in September - Marion, SD
  • Average rainfall days in September: 10.5 days

The months with the highest number of rainy days are May and June (16 days).
The month with the least rainy days is February (2.5 days).

Average snowfall in September
Marion, SD

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

The month with the highest snowfall is February (2.64").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Marion, SD

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

The month with the highest number of snowfall days is January (9.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Marion, 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: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).

Average sunshine days in September
Marion, SD

Average sunshine days in September - Marion, SD
  • Average sunshine days in September: 17.5 days

The month with the most sunshine days is November (22.5 days).
The month with the least sunshine days is June (11.5 days).

Average UV index in September
Marion, SD

Average UV index in September - Marion, SD
  • Average UV index in September: 4

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

Average cloud cover in September
Marion, SD

Average cloud cover in September - Marion, SD
  • Average cloud cover in September: 28

The month with the most cloud cover is January (Cloud cover 54).
The month with the least cloud cover is July (Cloud cover 25).

Average visibility in September
Marion, SD

Average visibility in September - Marion, 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).

Marion, South Dakota, USA

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