September weather forecast
Fort Pierre, SD

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Weather in September

September marks the dawn of autumn, bringing noticeable changes to Fort Pierre's weather landscape. A significant drop in temperature is noticed, falling from highs of 86°F (30°C) in August to a still comfortable 76.8°F (24.9°C). This month brings shorter days and less intense sunshine, signaling the end of the summer season. A beautiful blend of warm and cool breezes makes September ideal for scenic outdoor activities in Fort Pierre. The last traces of summer linger in early September, gradually fading as the month progresses.

Temperature

September is characterized by a reduction in the average high-temperature, from a hot 86°F (30°C) in August to a moderately hot 76.8°F (24.9°C). Fort Pierre encounters an average low-temperature of 57.4°F (14.1°C) during September nights.

Humidity

The months with the lowest humidity in Fort Pierre are August and September, with an average relative humidity of 52%.

Rainfall

In Fort Pierre, in September, it is raining for 8.9 days, with typically 0.67" (17mm) of accumulated precipitation. Throughout the year, there are 98.5 rainfall days, and 13.7" (348mm) of precipitation is accumulated.

Snowfall

June through September are months without snowfall.

Daylight

In Fort Pierre, the average length of the day in September is 12h and 30min.
On the first day of September, sunrise is at 6:05 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:39 am and sunset at 6:23 pm MDT.

Sunshine

In September, the average sunshine is 9h.

UV index

In Fort Pierre, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for the average person.
Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Heed the precautions - It is counselled to guard against solar damage. When the Sun is at its strongest around midday, find shade and limit exposure. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
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Frequently asked questions

What are September temperatures in Fort Pierre?

In Fort Pierre, 76.8°F (24.9°C) is the average high-temperature and 57.4°F (14.1°C) is the average low-temperature during September. The average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, in August is computed to be 87.8°F (31°C).

What are the least humid months in Fort Pierre?

August and September, with an average relative humidity of 52%, are the least humid months.

What is the average humidity in September in Fort Pierre?

The average relative humidity in September in Fort Pierre, South Dakota, is 52%.

How much does it rain in Fort Pierre in September?

In Fort Pierre, during September, the rain falls for 8.9 days and regularly aggregates up to 0.67" (17mm) of precipitation.

When it does not snow in Fort Pierre?

In Fort Pierre, South Dakota, snow does not fall in June through September.

Does it snow in Fort Pierre in September?

In Fort Pierre, South Dakota, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September in Fort Pierre?

The average day length in September in Fort Pierre, South Dakota, is 12h and 30min.

When is the sunrise / sunset in September in Fort Pierre?

On the first day of September in Fort Pierre, South Dakota, sunrise is at 6:05 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:39 am and sunset at 6:23 pm MDT.

How many hours of sunshine does Fort Pierre have in September?

In September, the average sunshine duration in Fort Pierre, South Dakota, is 9h.

What is the UV index reading in September in Fort Pierre?

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate health threat from unprotected exposure to 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
Fort Pierre, SD

Average temperature in September - Fort Pierre, SD
  • Average high temperature in September: 76.8°F

The warmest month (with the highest average high temperature) is July (88.7°F).
The month with the lowest average high temperature is January (26.2°F).

  • Average low temperature in September: 57.4°F

The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (12.6°F).

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Average pressure in September
Fort Pierre, SD

Average pressure in September - Fort Pierre, SD
  • Average pressure in September: 29.94"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

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Average wind speed in September
Fort Pierre, SD

Average wind speed in September - Fort Pierre, SD
  • Average wind speed in September: 11.1mph

The windiest month (with the highest average wind speed) is April (11.9mph).
The calmest months (with the lowest average wind speed) are February and August (9.9mph).

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Average humidity in September
Fort Pierre, SD

Average humidity in September - Fort Pierre, SD
  • Average humidity in September: 52%

The month with the highest relative humidity is January (85%).
The months with the lowest relative humidity are August and September (52%).

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Average rainfall in September
Fort Pierre, SD

Average rainfall in September - Fort Pierre, SD
  • Average rainfall in September: 0.67"

The wettest month (with the highest rainfall) is May (2.24").
The driest month (with the least rainfall) is January (0.35").

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Average rainfall days in September
Fort Pierre, SD

Average rainfall days in September - Fort Pierre, SD
  • Average rainfall days in September: 8.9 days

The month with the highest number of rainy days is June (14.2 days).
The month with the least rainy days is February (2.4 days).

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Average snowfall in September
Fort Pierre, SD

Average snowfall in September - Fort Pierre, SD
  • Average snowfall in September: 0"

The month with the highest snowfall is February (3.66").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in September
Fort Pierre, SD

Average snowfall days in September - Fort Pierre, SD
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (10 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
Fort Pierre, SD

Average daylight in September / Average sunshine in September - Fort Pierre, 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: 9h and 0min

The month with the most sunshine is July (Average sunshine: 11h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).

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Average sunshine days in September
Fort Pierre, SD

Average sunshine days in September - Fort Pierre, SD
  • Average sunshine days in September: 18.8 days

The month with the most sunshine days is November (22.3 days).
The month with the least sunshine days is June (13.7 days).

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Average UV index in September
Fort Pierre, SD

Average UV index in September - Fort Pierre, SD
  • Average UV index in September: 5

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are February and December (UV index 1).

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Average cloud cover in September
Fort Pierre, SD

Average cloud cover in September - Fort Pierre, SD
  • Average cloud cover in September: 21

The month with the most cloud cover is January (Cloud cover 50).
The months with the least cloud cover are July and August (Cloud cover 19).

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Average visibility in September
Fort Pierre, SD

Average visibility in September - Fort Pierre, 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).

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Fort Pierre, South Dakota, USA

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