September weather forecast and climate
Pierre, SD

The Capitol Dome building in Pierre, South Dakota, set in a beautiful tree park, reflected in the waterfront
The Capitol Dome building in Pierre, South Dakota, set in a beautiful tree park, reflected in the waterfront
The first month of the autumn, September, is also a moderately hot month in Pierre, South Dakota, with average temperature varying between 57.4°F (14.1°C) and 76.8°F (24.9°C).

Temperature

In Pierre, the average high-temperature decreases, from a hot 86°F (30°C) in August, to a warm 76.8°F (24.9°C). In September, in Pierre, the average low-temperature is 57.4°F (14.1°C).

Humidity

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

Rainfall

In Pierre, during September, the rain falls for 8.9 days and regularly aggregates up to 0.67" (17mm) of precipitation. In Pierre, during the entire year, the rain falls for 98.5 days and collects up to 13.7" (348mm) of precipitation.

Snowfall

In Pierre snow does not fall in June through September.

Daylight

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

Sunshine

The average sunshine is 9h.

UV index

In September, the average daily maximum UV index in Pierre is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to the UV radiation for the average person.
Note: The daily maximum UV index of 5 in September interpret into the following advice:
Take precautions - Protection against the skin and eye damage is obliged. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.

What is the temperature in September in Pierre?

The average high-temperature, in September, in Pierre, is 76.8°F (24.9°C), while the average low-temperature is 57.4°F (14.1°C).

What is the least humid month in Pierre?

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

What is the average humidity in September in Pierre?

In September, the average relative humidity in Pierre is 52%.

How many days does it rain in September in Pierre?

In September, in Pierre, South Dakota, the rain falls for 8.9 days. Throughout September, 0.67" (17mm) of precipitation is accumulated.

Does it snow in Pierre in September?

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

When it does not snow in Pierre?

June through September are months without snowfall.

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

The average length of the day in September in Pierre is 12.5h.

How many hours of sunshine does Pierre have in September?

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

What is the UV index reading in September in Pierre?

In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to the UV radiation.
Average temperature in September - Pierre, SD
  • Average high temperature in September: 24.9°C

The warmest month (with the highest average high temperature) is July (31.5°C).
The month with the lowest average high temperature is January (-3.2°C).

  • Average low temperature in September: 14.1°C

The month with the highest average low temperature is July (19.7°C).
The coldest month (with the lowest average low temperature) is January (-10.8°C).

Average pressure in September - Pierre, SD
  • Average pressure in September: 1014mbar

The month with the highest atmospheric pressure is January (1021.3mbar).
The month with the lowest atmospheric pressure is June (1010.5mbar).

Average wind speed in September - Pierre, SD
  • Average wind speed in September: 17.9km/h

The windiest month (with the highest average wind speed) is April (19.1km/h).
The calmest month (with the lowest average wind speed) is February (15.9km/h).

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

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

Average rainfall in September - Pierre, SD
  • Average rainfall in September: 17mm

The wettest month (with the highest rainfall) is May (57mm).
The driest month (with the least rainfall) is January (9mm).

Average rainfall days in September - 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).

Average snowfall in September - Pierre, SD
  • Average snowfall in September: 0mm

The month with the highest snowfall is February (93mm).
Months with the least snowfall are June, July, August and September (0mm).

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

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

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

The month with the longest days is June (Average daylight: 15.5h).
The month with the shortest days is December (Average daylight: 8.9h).

  • Average sunshine in September: 9h

The month with the most sunshine is July (Average sunshine: 11.5h).
The month with the least sunshine is January (Average sunshine: 4.6h).

Average sunshine days in September - 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).

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

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

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

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

Average visibility in September - Pierre, SD
  • Average visibility in September: 10km

Months with the highest visibility are May, June, July, August, September, October and November (10km).
Months with the lowest visibility are January, February, March, April and December (9km).