The Rock Hill region is going to feel a chill. How long will it last?

Serious autumn weather blew into the Rock Hill area Tuesday morning, carried by a northwest breeze that made temperatures feel more like December than mid-October.

A Freeze Warning is in effect Wednesday morning for York and Chester counties, with a Frost Advisory posted for Lancaster County.

Regardless of the type of warning, meteorologists say area residents will awaken Wednesday morning – and again Thursday – to temperatures near or below the freezing mark.

All of this is quite a shock, after Rock Hill recorded high temperatures of 79 degrees Saturday, 81 Sunday, and 79 Monday.

It won’t be the earliest freezing temperatures for Rock Hill, but the frost will be about three weeks earlier than normal.

“The coldest air of the season so far will continue to be ushered in, and it will bring about widespread freezing temperatures and frost for most of the week,” says Christiaan Patterson, of the National Weather Service office in Greer.

A big trough, or dip in the jet stream, is allowing cold air to surge southward from northern Canada into the eastern United States. Frost and freeze warnings are in effect all the way to the Gulf of Mexico.

The cold air, moving over the relatively warm waters of the Great Lakes, brought several inches of snow overnight to parts of Minnesota and Michigan’s Upper Peninsula.

Dry conditions are forecast all week in the Rock Hill region, but the cold air won’t go anywhere soon.

Tuesday’s forecast high of 58 degrees is 16 degrees below the Oct. 18 average of 74 in Rock Hill. Typically, daytime highs of 58 take place in early December or mid-February.

The northwest breeze that made temperatures feel even colder Tuesday is predicted to relax overnight. With temperatures tumbling, the calm conditions will be ideal for frost and a freeze, forecasters say.

Morning lows are expected to be in the range of 30-33 degrees both Wednesday and Thursday. That will, in effect, bring an end to the 2022 growing season locally.

Those temperatures also will threaten records in Rock Hill.

The record for Wednesday morning is 30, set in 1948. The record for Thursday morning is 32, set in 2015.

This cold snap isn’t unprecedented.

The earliest freezing temperature recorded in Rock Hill was a 32-degree reading on Oct. 7, 1935.

The cold snap is expected to abate by later in the week.

“Overnight temperatures should start to rebound a bit, starting Thursday (night) onward,” Patterson says. “For the weekend, fall-like temperatures return, with highs in the 60s and 70s.”

Under sunny skies, afternoon highs are predicted to reach the low to mid 70s both Saturday and Sunday.

This story was originally published October 18, 2022 at 3:28 PM.