PORTLAND – There was a time when Maine’s tourist season ran roughly from Memorial Day to Labor Day.

In recent years, though, September and October have come on as strong tourism months as well. Lodging revenues last year in September and October nearly equaled income for August. Traffic on the Maine Turnpike is as heavy in both September and October as it is in June.

Aaron Perkins, owner of The Dunes in Ogunquit, said his 36-room resort will stay busy after Labor Day. His guests will include more retirees, empty-nesters and couples without children.

International visitors come to watch the leaves turn orange and crimson. Most stores and restaurants around Ogunquit stay open through October, and the town holds its annual Cappriccio festival in early September.

Many visitors have learned over time that the Maine coast can be foggy and damp in June, Perkins said. They know rates tend to be cheaper after peak summer, and that the warmth of August can linger into September.

“We don’t really see things trail off until the end of October,” he said.

Tourism is Maine’s largest industry, in employment and overall sales. Travel by visitors and residents generated more than 181,000 jobs and nearly $4 billion in payroll, according to the state tourism office.

July and August remain the peak travel months, but business has been building during what the industry calls the shoulder seasons, particularly in September and early October.

One measure of tourism in those months is the money that overnight guests leave behind. Statewide lodging revenue figures from last year show $105 million collected in July and $103 million in August, with June ranking third, with $71 million.

But September’s revenues were noteworthy, at $60 million, and October brought in $40 million. Those numbers have business owners saying that a strong fall season can help make up for a slow June.

“If we have a strong September and October,” Perkins said, “it puts us over the top in terms of our budget for the year.”

But old notions die hard, and tourism officials are constantly trying to reinforce the idea that tourism season doesn’t come to a halt with the arrival of Labor Day.

In late May, television news reporters were standing on the northbound shoulder of the turnpike, talking about cars pouring into the state to kick off the tourist season. Come Labor Day, a similar account likely will be broadcast from the southbound lanes, as swarms of visitors head home.

“We’ve been trying to change that perception for years,” said Dann Lewis, the state’s tourism director.

Another benefit – for tourists, at least – about late-season travel is that visitors have a better chance for good weather in September than they do in June.

In Portland, for instance, September has an average of 10 clear days and 62 percent possible sunshine, according to Climatezone.com. By contrast, June has an average of six clear days and 56 percent sunshine. June also has more cloudy days on average than September, and more days of rain.