A warm and increasingly humid air mass will settle over the Lehigh Valley through Wednesday, with temperatures climbing into the upper 80s and potentially low 90s and increasing chances for scattered thunderstorms.

Temperatures across Massachusetts could cross 90 degrees on Monday as heat and humidity return to the Bay State. The surging temperatures on Monday are part of a broader warming trend in the state, which is expected to persist through Wednesday.

Due to the extreme heat and humidity expected, the NWS has issued a hazardous weather outlook for the entire state, as well as a heat advisory for southeastern New Hampshire. Specifically, areas under the advisory include Manchester, Nashua and Rochester.

This week will start on the warm side, with rain chances returning this afternoon in the extra humidity. The high pressure over the northeast is easing up and letting storm chances resume across the East Coast.

Heat and humidity continue building Monday through midweek, with inland areas climbing into the mid 90s and the coast in the low 90s. Dew points will reach the 60s, making it feel a bit muggy, but not as stifling as earlier in the summer.

First Alert Meteorologist Nick Lacour provides the latest look the searing heat, when to expect the humidity to return, and the latest on active tropical disturbances in the Atlantic basin.