RAPID CITY - The rapidly changing weather patterns seen in the past few days are something that Black Hills area residents should get used to as the fall season gets into full swing, according to a National Weather Service official.

"This is the time of year when we'll see quite frequent frontal passages and a lot of varying temps, from really nice mild days to fairly cool and windy days," said Matt Bunkers, a science and operations officer with the National Weather Service.

Temperatures dipped to 36 degrees at Rapid City Regional Airport through the evening Sunday into Monday morning then bounced back into the mid-50s on Monday afternoon.

Small amounts of rain were also seen in various areas of the Black Hills over the weekend, with under a quarter-inch falling in Rapid City and up to a half-inch in Custer and Fall River Counties.

Bunkers said cold fronts will be quite common during this time of year, with warm weather often sprinkled in before and after them.

"We're going to see cold frontal passages, and it's going to warm up pretty good ahead of these fronts and cool off and get windy behind the fronts," he said.

In fact, another such front will pass through the area this week, Bunkers said. He said the weather will be nice today and Wednesday but will cool down significantly Wednesday evening through early Thursday morning when another windy cold front arrives.

The cool air will stay around through Friday before warming up again for the weekend, Bunkers said.

Meanwhile, Spearfish Canyon has reached the first stages of its autumn colors, according to Jerry Boyer, a trustee with the Spearfish Canyon Society. Boyer said the canyon has reached about 15 percent of its color-changing phase.

"Leafy trees in the forest canopy are entering the lime phase while scattered oaks and the ground cover are beginning their burst to yellows," Boyer said. "Depending on the canyon's cool nights and rainfall, it appears 'peak colors' should arrive in the typical period between Sept. 27 and Oct. 3."

Predicted temperatures for Rapid City

Today: Mostly sunny, with a high near 75.

Wednesday: Mostly sunny, high near 86.

Thursday: Slight chance of thunderstorms - high of 53.

Friday: Mostly sunny, and a high of 56.

Saturday: Sunny, with a high near 73.

Sunday: Sunny, high near 78.

Source: National Weather Service

Contact Ryan Woodard at 394-8412 or ryan.woodard@rapidcityjournal.com