Clouds will be on the increase Monday as an onshore flow strengthens across New England. High temperatures will rise into the upper 70s to around 80 degrees, a bit cooler at the coast. It will feel humid given the moist air mass overhead.
Overnight, low clouds and fog will develop in response to a low pressure system reaching New England. Scattered showers will develop across eastern areas with continued mild and warm temperatures dropping down into the mid 60s, excluding Maine, where lows drop down a bit more, into the low 60s.
On Tuesday, morning clouds and isolated showers will give way to increasing sunshine from west to east through the afternoon. New showers and thunderstorms will develop where the sun is out for the longest, likely across western areas.
Highs are expected to reach into the low to mid 80s, possibly reaching the upper 80s in the Connecticut River Valley. Eastern Massachusetts and the Cape and Islands will only reach into the upper 70s, given the onshore wind and thicker clouds overhead. But we're expecting oppressive humidity as dew points rise into the lower 70s.
By Wednesday, what's likely to be the third heat wave of the summer will kick off across New England. Through Friday, highs will reach into the low 90s each day, with Thursday being the hottest day, with temperatures flirting with the mid 90s and a few locations reaching the upper 90s.
In addition to the heat, oppressive humidity levels will lead to heat indices reaching into the upper 90s to low 100s.
During this stretch, afternoon/evening showers and thunderstorms cannot be ruled out, given the warm and humid conditions. Any storms that do develop will carry torrential rains with isolated wind damage possible.
Looking ahead to the weekend, a cold front will bring some relief from the heat on Saturday, ushering slightly cooler and less humid air into New England. This front may stall over southern New England, leading to unsettled weather on the exclusive First Alert Weather 10-Day Forecast on NBC10 Boston and necn.