AUGUSTA, Maine — Bright, sunny skies and heavy southbound traffic are as certain to mark Labor Day in Maine as back-yard picnics, parades and end-of-summer visits to beaches.

Holiday weekend visitors also will wish they could extend their stay, with the National Weather Service predicting bright sunshine, a breeze and highs in the 70s or 80s on Monday, with prospects of a prolonged period of fair weather after that.

The near-perfect weather brings to a symbolic end Maine’s summer tourism season, which was marked by rain so relentless at times it caused rivers in Maine and other parts of northern New England to overflow their banks. High water created danger for canoeists and caused anglers to grumble. Portland had 4.7 inches of rain in July — 1.4 inches more than usual.

Rainfall for August didn’t set a record, but the 2.8 inches that drenched the Portland area on Aug. 3 was a record for that day, the National Weather Service in Gray said. Also in early August, rain-fed floodwater washed out a portion of a road and broke a water main in Freeport.

But neither the soggy weather nor high gasoline prices, which tailed off toward the end of the summer, seemed to discourage visitors who contribute to Maine’s largest industry, which accounts for $10 billion a year in sales. While no figures are available, state tourism officials said the state held its own, with heavy traffic in some regions and lighter-than-usual business in others.

“We’ve really had a pretty good season,” Brenda Wyatt of the Bar Harbor Campground on Mount Desert Island said Sunday. Wyatt said visits by recreational vehicle campers had been steady, but tent camping may be off a little. This holiday weekend looked very strong for business, she added.

The Maine Turnpike predicted about 158,000 vehicles would travel on the toll highway today, with a large share of them leaving the state between noon and 8 p.m. Between June 1 and Aug. 24, more than 17.7 million vehicles used the turnpike, about 1 million fewer vehicles — or 5.4 percent — than during the same period last year.

For those who call Maine home, formal and informal events marking the holiday were scheduled across the state.

The Western Maine Labor Council will hold a Labor Day Family Barbecue in Lewiston; the Eastern Maine Labor Council plans a Solidarity Bash in Brewer; and the Southern Maine Labor Council holds its holiday breakfast in Portland.

Political candidates scheduled holiday events to meet with the public. Sen. Susan Collins, R-Maine, who skipped her party’s national convention in Minnesota to kick off her campaign, planned to participate in the Oosoola Park Family Day parade, an annual Labor Day weekend event in Norridgewock.

U.S. Rep. Tom Allen, the 1st District Democrat who is challenging Collins for her Senate seat, planned to attend some of the organized labor groups’ events.