WINTER IN BRAZIL

SÃO PAULO, Brazil—When the mercury dips into the 50s and the palm trees along São Paulo's busy avenues seem to shiver in the breeze, that special season of the year has arrived in Brazil's biggest city: time to fantasize about winter.Though Brazil is a tropical country, winter gets an unexpected airing in São Paulo when the friozinho—or "little chill"—descends on the otherwise spring-like metropolis during the Southern Hemisphere's winter months. (click below to read more)

This week, parts of the U.S. are sweltering with huge heat waves as its summer begins. But as winter starts in Brazil, supermarkets in São Paulo are stocking Swiss-themed fondue sets and stacking them near cases of seasonally dark beer brews. Some enthusiastic winter worshipers donned jackets to ward off the morning chill—never mind that other Paulistanos on the sidewalk are still in shirt sleeves.

With the temperatures hovering around 68 and drizzly on Wednesday, winter might seem far off. Indeed, winter in São Paulo means mild average lows of 54 degrees and highs of 75. Local weather forecasters have a way of making it sound a bit more frigid:

"In winter, polar air masses come up from Antarctica over Argentina and Paraguay, and can hit São Paulo hard," said Alexandre Nascimento, a meteorologist with São Paulo's ClimaTempo weather service. Still, he predicts this winter will be mild, with only three or four of these cold air masses arriving.

São Paulo's winter season reaches its all-time highs in Campos do Jordão, an Alpine village-themed winter resort three-hours drive from São Paulo.

Nestled in a valley of planted pine trees, Campos is a cozy cluster of German-styled beer halls, Gruyere-perfumed fondue joints and timber-framed Swiss chalets with steep A-shaped roofs designed to bear the weight of heavy snow.

Snow isn't in the forecast. But at 5,300 feet above sea level, this subtropical Innsbruck is about as cold as it gets for miles around. On weekends, thousands of Brazilian winter seekers, many in scarves and knit caps, throng its cobbled streets in search of an authentic winter experience.

From atop the town's featured promontory, the roundish Elephant Hill, the gabled chalets and pine trees of Campos do evoke the Alps—only in spring. Birds chirp, flowers bloom, and a big thermometer planted nearby often reads in the mid-60s.

On Wednesday, it was rainy in Campos, raising hopes that a cold snap might be on its way, city officials said.

Pasquale Perrucci, a 45-year-old engineer from São Paulo, is among those heading to Campos this year with his family.

"I like to walk outside having my coat on," said Mr. Perrucci. But "I particularly like the winter in Brazil because it's not too intense."

That's good because most winter days in Campos are actually sunny and warm.

Night is the best time to catch a glimpse of winter. That's when the giant digital thermometers planted everywhere in Campos start clicking down the temperature. Tourists hope for a photo next to one reading somewhere below the crucial 10 Celsius mark—or 50 degrees Fahrenheit.

Some rare mornings, the gauges briefly touch the freezing point before the sun comes out to warm things up. Those days, São Paulo television crews arrive to deliver live reports by thermometers reading 0 Celsius.

Brazil's economic boom has put a taste of real winter in reach. More Brazilians are flying to Andes mountain ski resorts in Chile, where medics have noticed a spike in broken arms and other injuries due to the influx of novice skiers.

And more Brazilians are eating fondue, according to Paulo Lima, an innovation consultant at Brazil's Pão de Açúcar supermarket chain. Workers started stocking fondue sets in May, and several stores are already sold out. The fondue craze even hit Brazil's steamy northern beach towns, where locals crank up the air conditioning to hold tropical fondue parties, he said.

Theories vary on how winter worship crystallized in a country known for beaches and bikinis.

Some say it is the Brazilian knack for injecting zest into just about any experience, mild winters included. Others say winter's magical allure is multiplied for a population that would have to travel far to see real snow.

Still others say it is a nod to São Paulo's European roots. Immigrants from snowier climes like Italy, Spain and Germany populated the city in centuries past, and their descendants are proud of that heritage. A chalet in Campos do Jordão has been a must-have for the São Paulo elite since immigrant industrialist families began wintering there in the mid-1900s.

To be sure, many Paulistanos rue the winter. Three or four times a season, when the polar air masses gather, São Paulo winter produces what New Yorkers might recognize as yucky fall weather: Rain, dark clouds and temperatures in the 50s. And since few São Paulo buildings have heat, it is as cold inside as it is outside.

Still, conjuring a winter wonderland takes imagination. But some locals have developed ideas about what makes winter special. For example: Campos mayor Ana Cristina Cesar says enjoying winter isn't about being cold, it's about the fun of warming up.

"The cold brings you together, because you need someone special there to warm you. The other option is an electric blanket, but that's no fun," said Ms. Cesar. "The essentials are good company, sitting by a fire, a good wine and fondue."

Her office resembles a ski lodge, with a dark wood balcony jutting over one side of Campos's Elephant Hill. Adding to the effect, Elephant Hill is served by a working single-chair ski lift. People ride it to the scenic lookout at the top.

Old-timers such as town historian Pedro Paulo Filho swear Campos do Jordão was blanketed by real snow in 1928. He has a close-up photo of two toddlers standing in about an inch of snow to prove it.

Alas, most Brazilians have never seen snow. Mr. Perrucci saw it once, in a trip to Italy, with his wife. "It was beautiful. Everything looks different in the snow."

All the same, he said perhaps São Paulo's already hectic traffic is better off without it. Actual snow in São Paulo "would create a lot of problems."