When the temperature rises in South Florida, revenue drops at many businesses. Along Las Olas Boulevard in Fort Lauderdale and Lincoln Road in Miami Beach, pedestrians typically avoid strolling in the torturous humidity, forcing store owners and restaurateurs to survive the off-season with marketing gimmicks and cost cutting.

And yet, there is a pocket of South Florida’s economy that calls summer its busy season. These companies count on revenue made during these few months to put them in the black for the year. This year, getting the most in peak months could be crucial with recent indications that the recession across Europe may drag down the economy here as well.

“I think we’re becoming more convinced 2012 is not going to provide us with an economic boost,” says University of Central Florida economist Sean Snaith. “Most likely, our economy will continue to recover in a much-subdued pace. So, if summer is your high time, you must get as much revenue as you can.”

Gauging our area’s seasonality is tricky. Weather, tourists and economic trends factor into sales in unexpected ways. Up north, outdoor furniture retailers get a pop of revenue in summer, but in South Florida, those businesses report winter and spring — the cooler months here — are their busier sales periods.

Then there’s the language-instruction business. In most markets, customers, particularly corporate clients, pull back on classes over the summer months to take vacation. Yet, Ramon Lopez, Southeast market area director for Berlitz, says his Coral Gables, Brickell and Boca Raton offices get a boost in business during summer from international customers. They come from Latin America and Europe, have homes here and want to learn English, he says. They enroll themselves and their children in classes that include total immersion, private instruction and group lessons.

“The summer months can be important to our bottom line,” Lopez says. “This year, June started slow, but it’s looking good for July and August. We have a lot of repeat customers coming from Brazil and Venezuela.”

Then there’s the business of recreation. While tourists escaping the cold and corporate convention guests keep waterfront hotels, tiki bars and cabanas buzzing during winter and spring, they taper off in summer. But for the locals and those tourists who dare to spend the day outside in the South Florida heat, Jet Ski rentals remain a logical choice.

Adam Burnett, manager of American WaterSports, operates two water-bike rental locations — one in South Beach, the other in Coconut Grove. Renters pay $69 for a half-hour rental and $109 for a full hour. A one-hour water-bike tour brings in $119 per person.

Burnett’s company, which relies on local hotels and Internet searches for referrals, has begun featuring a discount coupon on its website to lure price-sensitive customers. Examining his revenue over a year, Burnett sees his big spike in June. He considers himself fortunate compared with water-bike rentals in other U.S. cities: His business picks ups from late February to late September as opposed to water-bike rentals in other towns, where the busy season runs only from June through August.

Some people prefer to buy rather than rent water bikes and boats. This year, the sputtering economy has affected buying habits, says John Vogel of Jet Ski of Miami and Fisherman’s Boat Group. Vogel says summer is buying time for those interested in ocean fun and this year, his lower-priced items are more in demand — the more affordable Jet Skis and small leisure boats. “The bigger boats are still selling, but they are not as popular this year,” he says.