In the storied cycle of seasons in Paris, no month is more rooted in the French character, and in the tourist's perception, than the deadness of August.

For generations, the city has emptied on the first of August as if from a plague--the plague of work. You can walk for blocks without finding a retail business open. Traffic is eerily light. Factories shut down. Phones go unanswered. The hot sun on empty sidewalks colors Paris in Latin hues.

In some ways, this is still the case. But a lot of Parisians are struck by how many other Parisians are around this month--and many are wondering whether the city's love affair with the August vacation is fading.

Du Cote 7eme, a neighborhood bistro on the Left Bank, is open this month for the first time and has been stunned by the brisk business it is doing. "We decided to give it a try this year," manager Martial Barrie said. "Some of us thought we'd get no one, but we're only about 20 percent off what we normally do. It's a big success for us."

At the Coucaud butcher shop a few blocks away, the lady at the cash register has definitely noticed the phenomenon. "The people I know took their vacations in July--that's when we had our real slump--or they'll take them in September," she said.

Consultant Nicolas Rousseaux has been working in Paris for 23 years, and he can feel the August difference. "I can reach people on the phone; 10 years ago, that was impossible," he said. "This morning, I had to go around the block two or three times to find a parking place. . . . It's amazing!"

The sociology of the French vacation, dating from the institution of legalized holidays for French workers more than 60 years ago, is distinctive and tenacious. This industrious economic power, the fourth-largest in the world, is not embarrassed to take five--weeks, that is, the minimum vacation, which is among the longest in Europe. Many workers get six or seven weeks, and for years almost everyone has designated August as the time to take off.

But new forces--European integration, a globalizing economy, changes in the school calendar, revolutions in tourism, even a shrinking French work week--are eroding the sacrosanct position of the eighth month. Not that France is vacationing less. "The French are going on fewer long vacations but taking shorter vacations more often," said polling analyst Stephane Rozes of the CSA research firm.

Tourism and labor figures collected by the government show that the length of July and August vacations shrank by 14 percent between 1990 and 1997. Increasing numbers of people here are vacationing two, three, even four times a year. The introduction of a 35-hour work week at constant salaries will mean more leisure time, analysts say, but not necessarily August leisure time.

"People have had it with August," said Barrie as he surveyed his bistro clientele. "They don't need to wait for August to find the sun."

School schedules under France's tight central administration have played a role in changing national habits, extending the school year but larding it with vacations. Ample school breaks and cheap air fares give big incentives to French families to travel during a week-long break at All Saints Day, Nov. 1. So does another innovation affecting a new generation of French children--a full two-week break in February, which is ideal for ski holidays. Then there's another two-week school holiday in May.

More noticeable this month in Paris, where one in six French citizens lives, is that vacationers are returning sooner: a perceptible trickle on Monday, Aug. 9, a palpable surge the following Monday, and a definite buzz of activity last week.

Early returning Parisians are encountering a record influx of tourists, especially Americans taking advantage of an exchange rate of more than six francs to the dollar. Their presence, too, is persuading more French businesses to stay open in August.

The early stir of activity in Paris may also be a spillover of cultural habits across European borders. Big corporate and banking mergers involving French companies this summer have kept many people in their offices, as have the demands of world stock and currency markets.

The need to stay in touch with associates in countries not married to the August vacation, or even the desire to evince a "European" spirit that counters perceptions of institutionalized French sloth, are bringing more people back to Paris in August.

"I have to be here; I can't leave for a month," said Rousseaux, the consultant, whose business clients include Austrian, American and British companies. He said that one of his foreign associates was complaining about his inability to meet with enough people during a visit to Paris earlier this month--"but he still got a lot of meetings, and not very long ago he wouldn't have."

Many Parisians, particularly old-timers, don't buy this. They cherish the idea of a universal vacation and a city closed for business in August. As the manager of an eyeglass store in central Paris remarked, "It's still a desert out there." A garage mechanic who always stays open in August said his business had been exactly the same--that is, slack.

After hours of trying to get someone to answer the phone at Peugeot, the French automaker, Sebastien Eymann of the human resources department came on the line to explain that "almost everybody is gone. All the people who could answer your questions are currently on vacation." But for how long?

Researcher Daphne Benoit contributed to this report.

CAPTION: Parisians who remained at home this August jam a Left Bank vegetable market on a recent Sunday morning.