A sunny Fourth of July weekend across Maine followed by a heat advisory Monday will give way to downpours, thunderstorms and slightly cooler temperatures this week, the National Weather Service says.

While rain is on the way, the remnants of Chantal — which wreaked havoc in North Carolina over the weekend as a tropical storm and is now headed north as a weaker tropical depression — are unlikely to have much effect on Maine, forecasters said Monday.

High temperatures across Maine climbed toward the 90s on Monday afternoon, with temperatures reaching the low 80s in Portland, 86 degrees in Lewiston-Auburn and 91 degrees in Sanford. The heat index — the measure of how hot it actually feels — reached 98 degrees in Sanford at one point Monday, with many other towns reaching the low 90s.

Jon Palmer, a meteorologist at the National Weather Service’s Gray office, said Monday’s heat will be followed by some storms in the southern portion of the state Tuesday.

“We’ll have some widespread rain and thunderstorms moving through the area,” Palmer said. “The main threats for (Tuesday) are looking like heavy downpours.”

Palmer said some localized flooding could be possible as the storm develops throughout the day. The precipitation should generally be limited to the southern portion of the state, he said, with a heftier impact on the coast.

Northern and eastern Maine were already getting some rain Monday afternoon, with more coming for the Bangor area and Washington County overnight into Tuesday morning, said Anne Strauser, a meteorologist at the weather service office in Caribou.

“(Monday’s) the last really hot day for the Bangor area,” Strauser said. “The rain pushing in (Monday night) and (Tuesday) will help cool things down.”

Those storms likely won’t reach southern Maine until Tuesday morning at the earliest, Palmer said.

The system impacting Maine is separate from what’s left of Chantal, which was downgraded to a tropical depression Sunday after making landfall in North Carolina. Still, the storm left severe flooding in its wake, with between 3 and 8 inches of rain falling across parts of the state Sunday into Monday morning, according to North Carolina Emergency Management.

The storm has displaced more than 60 people in the college town of Chapel Hill, where the fire department and neighboring agencies made more than 50 water rescues. An 83-year-old woman was killed when floodwaters swept her car about 100 feet off a rural road Sunday night.

Strauser said the northern part of Maine is unlikely to see any lingering impacts from the tropical depression.

“This system that’s giving us the storms right now will move offshore before (Chantal) can pull all of that rain into our area,” Strauser said. “The rain from the tropical system is projected to stay well off our coast.”

Palmer also doubted Chantal would have any major impacts on the southern part of the state, other than some extra moisture, which could contribute to Tuesday’s precipitation.

“It looks like Chantal is going to dissolve before it reaches New England,” Palmer said, “but moisture from its remnants could allow for thunderstorms and produce a lot of heavy rain (Tuesday) night.”

There are significantly lower chances of rain in the mountains Tuesday, Palmer said, with the northwest corner of Maine potentially staying completely dry.

Temperatures for much of the southern part of the state are projected to be in the upper 70s and low 80s the rest of the week, Palmer said.

Early forecasts from the National Weather Service call for a partly sunny Saturday and Sunday, with temperatures in the mid-70s, across the Portland area.

This report contains material from The Associated Press.