The heat wave headed to Maine will kick in Wednesday afternoon, but AccuWeather meteorologist Joe Lundberg says the core of the heat will happen on Thursday and Friday.

“That’s when the nose, this upper-level ridge of high pressure, points its way eastward to the eastern seaboard, and we get a kind of a west to southwest flow aloft, and that just going to bring the heat and the humidity into the area for Thursday and Friday,” said Lundberg. “And it will linger into the start of the Independence Day (Saturday) before it starts to cool off a little bit.”

The heat wave started in the Midwest, where cities like Chicago are now going through extended Extreme Heat Warnings.

Once the heat hits New England, Boston is forecast to be hotter than Portland for a longer period on time.

Lundberg says especially warm weather will continue, which won’t likely subside for the rest of July.

“There’s really nothing cool in the pipeline, in terms of what I’m looking at in the forecast,” Lundberg said. “So, I think temperatures for the month on average, for the month of July are going to be above average, probably by I’d say two to three degrees for the month as a whole,”

Portland is likely to experience an official heat wave this week, which is defined by three consecutive days at or above 90 degrees.

Lundberg noted the risk of thunderstorms, especially on Saturday and Thursday, which could alleviate the heat but also pose a risk of drought if rainfall is insufficient. He emphasized the need for consistent rainfall to avoid drought conditions this summer