Hot weather that has scorched the nation’s heartland is making its way to the nation’s northeastern tip, where temperature could hit 100 this weekend in parts of northern New England.

The temperature already topped 90 degrees in parts of Vermont and New Hampshire on Friday. By Saturday, hot weather and oppressive humidity will be enveloping the entire region.

Officials are warning residents to avoid rigorous outdoor activities because of unhealthy air.

Cooling shelters are being opened in a region where many residents do not have air conditioning.

In some places, the temperature could close in on 100 degrees. The last time the temperature hit 100 in Portland, Maine, was on July 22, 2011.