Celebrated on June 23–25, this festivity overlaps with friaje during this time—winds that originate in the southern Atlantic and the Patagonia, sweeping northwest and across the Amazon basin  with temperatures to as low as 8°C.
These cold spells or friajes can happen anytime from May to August but are most common around San Juan’s birthday in late June. Don’t expect to see many animals during a friaje—the monkeys huddle up together in balls to stay warm and the birds roost until it’s all over.
The religious and meteorological coincidence has merged over the centuries into Iquitos ’s biggest party, celebrated these days at the Mercado Artesanal de San Juan on the way to the airport. Dance competitions from indigenous groups and rock concerts are enjoyed while eating juanes, rice tamale-like bundles of chicken, tomato, and onion wrapped in a bijao palm leaf, which imparts a delicious flavor to the concoction.
A sweater or a windbreaker is quite handy, because los vientos de San Juan “the winds of San Juan” make the place feel more like Seattle or London than Iquitos.
Iquitos  also has a Founders Day celebration on January 5 and a Carnaval in late February or early March. Santo Tomás has a handicraft fair on August 21 and festival in honor of its patron saint September 23–25.