A week after parts of the Pittsburgh region saw frost advisories and freeze warnings, near record heat is expected for the start of the new week.

A high of 9o-to-91 degrees is forecast for Monday, and a high around 90 is expected on Tuesday, National Weather Service meteorologist David Shallenberger said.

That’s about a 35-degree swing from the high of 56 on Thursday, and almost 20 degrees higher than the normal high of 72.

The weather service says there will be an increased risk for heat-related impacts, especially to vulnerable populations.

For Monday, the record high of 91 dates from 1962. The record for Tuesday, 93, goes back even further, to 1877.

The heat wave is short-lived, with Wednesday’s high forecast to be 77-to-78 degrees. Shallenberger said that is still above normal.

It also won’t be cooling off much overnight for the next few days, which meteorologist Andrew Kienzle said could add to heat stress.

After highs in the mid-to-high 80s Sunday, Pittsburgh will see a low in the low 60s, he said. For Monday and Tuesday nights, the lows are expected to be in the upper 60s, with some areas not getting below 70, Kienzle said.