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United StatesThe weather in September in Rapid City
It's warm in September in Rapid City with an average temperature of 25°C. Temperatures this month range from a low of 21°C to a high of 31°C. At night, you can expect temperatures between 9°C and 16°C.
Looking for great weather? September is a good time to be in Rapid City. The temperatures are nice, and there’s not too much rain.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in September for Rapid City, South Dakota. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 40°C in 2020, Rapid City reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 3°C in 2014. The extreme nighttime temperatures ranged from a lowest recorded value of -3°C to a highest value of 20°C.
Rainfall amount
In September, there is an average of 59 mm of precipitation, spread over 9 days. The wind speed is around 5 Bft, mostly coming from the Southwest.
Daily weather in September for Rapid City
Click on any day in September to get detailed info about the usual weather on that day in Rapid City. Check out the historical temperatures and precipitation over the past 10 years on this day.
September weather comparison
| Rapid City | New York | |
|---|---|---|
| Average temperature | 25°C | 27°C |
| Max. temperature | 31°C | 31°C |
| Min. temperature | 9°C | -5°C |
| Total precipitation | 59 mm | 57 mm |
| Rainy days | 9 days | 9 days |
Start of September
The month of September starts in Rapid City with hot temps, averaging around 28°C during the day and nights around 13°C.
Mid September
By mid-September, daytime temps drop to around 26°C, with nights around 11°C. Not much precipitation expected during this period. It’s mostly dry and sunny.
End of September
By the end of September, the average daytime temperature in Rapid City is around 23°C, while nighttime temps are about 10°C. Expect regular precipitation, but if you’re lucky, you’ll also get some dry and sunny days.
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UV index
The UV index is a maximum of 5 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.
Check out the climate of Rapid City for all months and discover the best travel time
Temperature charts
These charts show the average temperatures in September in Rapid City, South Dakota. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in September in Rapid City
Temperature in September in Rapid City over the years
Precipitation charts
These charts show the average amount of precipitation in September in Rapid City, South Dakota. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in September in Rapid City
Total precipitation in September in Rapid City over the years
Daily UV index in September in Rapid City
This chart shows the average daily UV index in September in Rapid City, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in September in Rapid City
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Average weather in Rapid City by month
Click on a month below to see detailed weather info for Rapid City. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.