September weather forecast and climate
Saint Francis, SD

Weather in September

September, the first month of the autumn, in Saint Francis, is still a warm month, with average temperature fluctuating between 55.8°F (13.2°C) and 75.7°F (24.3°C).

Temperature

In September, the average high-temperature slightly decreases, from 84.6°F (29.2°C) in August, to a still moderately hot 75.7°F (24.3°C). The average low-temperature, in Saint Francis, is 55.8°F (13.2°C).

Humidity

With an average relative humidity of 56%, September is the least humid month in Saint Francis.

Rainfall

In Saint Francis, in September, during 10.2 rainfall days, 1.14" (29mm) of precipitation is typically accumulated. Throughout the year, in Saint Francis, there are 109.2 rainfall days, and 16.89" (429mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, September through December. September is the first month it typically snows in Saint Francis. Throughout September, in the average 0.1 snowfall days, it receives 0.2" (5mm) of snow. In Saint Francis, during the entire year, snow falls for 41.1 days, and aggregates up to 14.53" (369mm) of snow.

Daylight

In September, the average length of the day is 12.5h.

Sunshine

In Saint Francis, the average sunshine in September is 9.1h.

UV index

In Saint Francis, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from the exposure to the Sun's UV rays for ordinary individuals.
Note: In September, the average maximum UV index of 5 translate into the following recommendations:
Take precautions - Protection against sunburn is recommended. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
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FAQ

What is the least humid month in Saint Francis?

With an average relative humidity of 56%, September is the least humid month in Saint Francis.

What is the average humidity in September in Saint Francis?

The average relative humidity in September is 56%.

How much does it rain in Saint Francis in September?

In Saint Francis, South Dakota, in September, during 10.2 rainfall days, 1.14" (29mm) of precipitation is typically accumulated.

When does it start snowing in Saint Francis?

September is the first month it typically snows in Saint Francis. Throughout September, in the average 0.1 snowfall days, it receives 0.2" (5mm) of snow.

What is the average length of the day in September in Saint Francis?

The average length of the day in September in Saint Francis, South Dakota, is 12.5h.

How long on average sun shines in September in Saint Francis?

In September, the average sunshine in Saint Francis, South Dakota, is 9.1h.

How high is the UV index in September in Saint Francis?

In September, the average daily maximum UV index in Saint Francis, South Dakota, is 5. A UV Index of 3 to 5 symbolizes a medium hazard to health from the exposure to the Sun's UV radiation.

Average temperature in September
Saint Francis, SD

Average temperature in September - Saint Francis, SD
  • Average high temperature in September: 75.7°F

The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (31.5°F).

  • Average low temperature in September: 55.8°F

The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).

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Average pressure in September
Saint Francis, SD

Average pressure in September - Saint Francis, SD
  • Average pressure in September: 29.95"

The month with the highest atmospheric pressure is January (30.15").
The month with the lowest atmospheric pressure is June (29.85").

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Average wind speed in September
Saint Francis, SD

Average wind speed in September - Saint Francis, SD
  • Average wind speed in September: 11.7mph

The windiest month (with the highest average wind speed) is April (13.1mph).
The calmest months (with the lowest average wind speed) are July and August (10.6mph).

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Average humidity in September
Saint Francis, SD

Average humidity in September - Saint Francis, SD
  • Average humidity in September: 56%

The month with the highest relative humidity is January (78%).
The month with the lowest relative humidity is September (56%).

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Average rainfall in September
Saint Francis, SD

Average rainfall in September - Saint Francis, SD
  • Average rainfall in September: 1.14"

The wettest month (with the highest rainfall) is May (2.6").
The driest month (with the least rainfall) is January (0.47").

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Average rainfall days in September
Saint Francis, SD

Average rainfall days in September - Saint Francis, SD
  • Average rainfall days in September: 10.2 days

The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is January (2.4 days).

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Average snowfall in September
Saint Francis, SD

Average snowfall in September - Saint Francis, SD
  • Average snowfall in September: 0.2"

The month with the highest snowfall is December (2.76").
Months with the least snowfall are June, July and August (0").

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Average snowfall days in September
Saint Francis, SD

Average snowfall days in September - Saint Francis, SD
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is January (9.7 days).
Months with the least snowfall days are June, July and August (0 days).

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Average daylight in September /
Average sunshine in September
Saint Francis, SD

Average daylight in September / Average sunshine in September - Saint Francis, SD
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.3h).
The month with the shortest days is December (Average daylight: 9h).

  • Average sunshine in September: 9.1h

The month with the most sunshine is July (Average sunshine: 11.2h).
The month with the least sunshine is January (Average sunshine: 5.4h).

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Average sunshine days in September
Saint Francis, SD

Average sunshine days in September - Saint Francis, SD
  • Average sunshine days in September: 17.2 days

The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is June (11.2 days).

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Average UV index in September
Saint Francis, SD

Average UV index in September - Saint Francis, SD
  • Average UV index in September: 5

Months with the highest UV index are June, July and August (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 2).

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Average cloud cover in September
Saint Francis, SD

Average cloud cover in September - Saint Francis, SD
  • Average cloud cover in September: 21

The month with the most cloud cover is February (Cloud cover 44).
Months with the least cloud cover are July, August and September (Cloud cover 21).

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Average visibility in September
Saint Francis, SD

Average visibility in September - Saint Francis, SD
  • Average visibility in September: 6mi

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

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