Unseasonable warmth is record-breaking, but very cold air lurks for the Lehigh Valley

• The Lehigh Valley tied a record-high temperature on Thursday
• Another day of record-setting warmth is anticipated Saturday
• We flip the script next week with highs in the 40s and a hard freeze expected

BETHLEHEM, Pa. — The Lehigh Valley was among six climate sites in the region that tied or established record-high temperatures Thursday, and more records are in jeopardy this weekend.

The mercury hit 78 degrees at Lehigh Valley International Airport at 2:36 p.m. Thursday, tying a record established for the date in 1947, 1952 and 1963.

The climate site in Reading hit a record high of 81, and Philadelphia hit 80 degrees. That smashed an old record high for the date set in 1920.

The National Weather Service said high pressure anchored to our south is forecast to bring one more unseasonably warm day on Saturday.

Highs are expected to favor the upper 70s and lower 80s, with record highs possible at most locations.

The Lehigh Valley’s mark to beat Saturday is 80 degrees, set in 1984.

“Because the record highs aren’t quite as high on Saturday, I think you’re going to have another day like [Thursday] where we smashed those records,” EPAWA meteorologist Bobby Martrich said in his latest video update.

It will be the perfect day to get out and see fall color at peak in Lehigh and Northampton counties, with the leaves forecast to be at "best color" through next week.

Flipping the script

A cold front is expected to arrive late on Saturday, erasing the last of this big-time warmth. It will bring an increasing chance of rain from late Saturday night into Sunday night, forecasters say.

“This frontal boundary is going to be very slow to move through,” Martrich said. “But the cold air is going to win out.”

That means a temperature range across the region Sunday where highs could be in the 50s in the Poconos, the lower 60s in the Lehigh Valley, and in the upper 60s to low 70s in the Interstate 95 corridor and points south.

The Lehigh Valley also is likely to see showers move through.

“Probably a lighter shower type thing, not an all-day washout or anything like that,” Martrich said.

“Monday, I do think some of these areas [across the region] do get involved in some of these showers as the front is finally pulled through the region, and that will come through on Monday night.”

Hard freeze ahead

“We do have some very cold temperatures moving in here for next week,” Martrich said, flagging the Tuesday through Thursday time frame.

“We’re going to flip the script from very warm, obviously very above average temperatures this week and then you have all these cold temperatures — colder, below average, well below average temperatures — coming in here next week.”

Hard freezes are likely, especially with daytime highs in the 40s on Wednesday and overnight lows in the lower 30s and perhaps the upper 20s.

The weather service predicts the overnight low Wednesday into Thursday will be just 29 degrees.