You can head to Brazil, the famous, carnival melting pot, at any time of year. From April to October, the weather is warm and dry on the coast, but cold in the south. It's hot everywhere from December to March. Be forewarned that the country is invaded by Brazilian tourists between December and February, as it's their summer break. As local climates greatly differ, you can look at weather patterns for the region you want to visit, or you can organise your departure according Brazilian festival dates!