Rio de Janeiro is at sea level, near the Tropic of Capricorn. It has a hot and damp tropical climate. Being on the Southern Hemisphere, the seasons are reversed, as in Australia and Africa.Summer is probably Rio's most popular season. It starts to get hotter around October, and summer vacations start in mid-December. On sunny days, digital thermometers in Ipanema and Copacabana may read 40° C, about 104 F. If you do not turn on the air conditioner, when you leave the shower start wondering if you forgot to towel off, or if you're already breaking a new sweat!