Black Hills Weather: What can we expect for September?

Here are the stats for the upcoming month.

Well folks, today is the last day of August. Today is also the last day of the Meteorological Summer. September here in Rapid City brings some cooler changes, and yes, we do average a little bit of snow.

Let’s dive into the details.

FIRST OF ALL: September 1st is the 1st day of the Meteorological Fall. Now, you’re asking what is the difference between Meteorological Fall, and the Calendar first day of fall? Simply put, Meteorologists and Climatologists use the Meteorological Season for data purposes. It’s easier to go from September 1st – November 30th as opposed to September 22nd – December 21st. The First and last day of Fall doesn’t fall on the same day every year, so to record seasonal data it can get involved. So, for that reason, OUR first day of fall is tomorrow.


TEMP: The Month of September will start off with an average high of 82, with an average low of 52. By the end of the month, the average High and Low will drop to 68 and 40 respectively. I’m not sure about you, but 40’s and 50’s are enough for me to break out a sweater.

PRECIPITATION: In terms of precipitation, WHICH WE DESPERATELY NEED ACROSS THE AREA (You don’t need me to tell you that, you can just look at your lawn), we do average just over an inch of Precip. 1,29″ to be exact.

In terms of Extreme Precipitation, if you go 1975, that was the year with the LEAST precipitation with 0.03″ for the entire month. YIKES!! Now for the opposite end of the spectrum. To find the big winner, you have to turn the page several years, all the way to 1946. There, you will see a good soaking. 3.94 inches of precipitation fell for the entire month of September.

SNOWFALL: Ahhh yes, snowfall. Ladies and Gentlemen, we average 0.2″ of snow for the month. So yes, I am saying there’s a chance of seeing snow in September! (But we are in the Black Hills, that is somewhat expected.)
In terms of the extremes, with the exception of 1970, 1965, 2000, 1985, 1984, 1983, 1961, 2014, 1996, 1995, 1993, 1991, 1966, 1962, 1960, 1959, 1957, 1955, 1951, 1950, and 1949, the years NOT listed since 1948 didn’t see any snow for the month. **DISCLAIMER: According to Cli-Mate, 5 years were missing: 2001, 2002, 2003, 2004, 2019**
The Maximum amount of snow for the month of September was 2″ set back in 1970. (2014, 1996, 1995, 1993, 1991, 1966, 1962, 1960, 1959, 1957, 1955, 1951, 1950, and 1949 all reported only a trace of snow for the month. Hey, it still counts!)

SUNRISE/SUNSET: Are you a big fan of the long days? Maybe you’re going out and playing a nice late afternoon round of Golf? (I see you over there Bob Riggio!!!) Well, enjoy it while you can! The Sunrise/Sunset as of September 1st is 6:16 AM – 7:30 PM Respectively, which gives us 13 Hours, 14 Minutes of Daylight. By the end of the Month, the Sunrise/Sunset is 6:49 AM – 6:36 PM which gives us only 11 Hours, 47 Minutes of Daylight. We will lose 1 Hour, 27 Minutes of Daylight throughout the entire Month.

HEADS UP: The last 7:00 PM Sunset will be on Thursday, September 17th (Which is also a New Moon). The Next 7:00 PM Sunset will occur on Tuesday, March 16th (2 days after Daylight Saving Time Begins.)

WHAT DO YOU THINK? With this information that I have given to you, I have to ask, when you think the 1st inch of snow will fall in Rapid City? (It has to be observed AT THE AIRPORT for it to count!) Submit your guess to me at, or Brant at

Feel free to follow me on Facebook, and at Twitter @ErikDeanWX
Also, feel free to follow Brant on Facebook and Twitter @BrantBeckmanWX

Tomorrow, we will dive into the “Summer” that was in terms of stats.


Enjoy the rest of your Monday!

-Meteorologist Erik Dean

Categories: Local News, South Dakota News, Weather Daily