Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September witnesses a gentle descent in average high-temperature, descending from August's pleasant 72.1°F (22.3°C) to an enjoyable 66.4°F (19.1°C). Throughout September nights, Rapid City experiences a consistent temperature average of 54.5°F (12.5°C).Humidity
In September, the average relative humidity is 78%.Rainfall
In Rapid City, in September, it is raining for 12.6 days, with typically 1.81" (46mm) of accumulated precipitation. In Rapid City, during the entire year, the rain falls for 136.2 days and collects up to 24.65" (626mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Rapid City, the average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 7:04 am and sunset at 8:17 pm. On the last day of September, sunrise is at 7:38 am and sunset at 7:22 pm EDT.
Sunshine
In September, the average sunshine in Rapid City is 8.1h.UV index
In Rapid City, the average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: In September, the UV index of 3 transforms into the following advice:
Put precautions into practice - Guidance to elude sunburn is provided. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Rapid City in September?
What is the average humidity in September in Rapid City?
How many days does it rain in September in Rapid City?
When it does not snow in Rapid City?
Does it snow in Rapid City in September?
What is the average length of the day in September in Rapid City?
What time are sunrise and sunset in September in Rapid City?
How many hours of sunshine does Rapid City have in September?
What is the UV index intensity in September in Rapid City?
Average temperature in September
Rapid City, MI
- Average high temperature in September: 66.4°F
The warmest month (with the highest average high temperature) is August (72.1°F).
The month with the lowest average high temperature is January (25.7°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is August (60.4°F).
The coldest months (with the lowest average low temperature) are January and February (18.9°F).
Average pressure in September
Rapid City, MI
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Rapid City, MI
- Average wind speed in September: 9.4mph
The windiest months (with the highest average wind speed) are January, November and December (12.6mph).
The calmest month (with the lowest average wind speed) is July (7.8mph).
Average humidity in September
Rapid City, MI
- Average humidity in September: 78%
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are April and May (77%).
Average rainfall in September
Rapid City, MI
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is October (2.91").
The driest month (with the least rainfall) is February (1.54").
Average rainfall days in September
Rapid City, MI
- Average rainfall days in September: 12.6 days
The month with the highest number of rainy days is October (17.9 days).
The month with the least rainy days is February (3.9 days).
Average snowfall in September
Rapid City, MI
- Average snowfall in September: 0"
The month with the highest snowfall is January (6.57").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Rapid City, MI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (21.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Rapid City, MI
- 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: 8h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 1h and 42min).
Average sunshine days in September
Rapid City, MI
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is May (14.7 days).
The month with the least sunshine days is January (4.7 days).
Average UV index in September
Rapid City, MI
- Average UV index in September: 3
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in September
Rapid City, MI
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 83).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Rapid City, MI
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).
Rapid City, Michigan, USA
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