Climate of Rio de Janeiro

Climate of Rio de Janeiro
Rio has a tropical savanna climate that closely borders a tropical monsoon climate according to the Köppen climate classification, and is often characterized by long periods of heavy rain from December to March.
 In inland areas of the city, temperatures above 40 °C (104 °F) are common during the summer, though rarely for long periods, while maximum temperatures above 27 °C (81 °F) can occur on a monthly basis.

Along the coast, the breeze, blowing alternately onshore and offshore, moderates the temperature. Because of its geographic situation, the city is often reached, especially during autumn and winter, by cold fronts advancing from Antarctica, causing frequent weather changes. It is mostly in summer that strong showers provoke catastrophic floods and landslides. The mountainous areas register greater rainfall since they constitute a barrier to the humid wind that comes from the Atlantic.

It is said that the city had frosting sometime in its past, but it was never confirmed. Some areas within Rio de Janeiro state have hail with an even frequency (the phenomena is definitely not rare or limited to a few regions, happening in the metropolitan area and western suburbs of the city),  said to be approximately each two decades or less in some regions, and in others there is snowfall more than one time in each century, most commonly in the cities of Resende and Itatiaia (in lower latitudes than Rio de Janeiro, but way higher altitudes), nation's coldest ones outside Southern Brazil, and the most propitious to frosting.

The average annual minimum temperature is 21 °C (70 °F), the average annual maximum temperature is 27 °C (81 °F), and the average annual temperature is 23 °C (73 °F). The average yearly precipitation is 1,175 mm. According to INMET, the minimum temperature recorded was 4.8 °C (41 °F) in July 1928, in the Campo dos Afonsos bairro (the Portuguese word for neighbourhood), and the absolute maximum was 44 °C (111 °F) in February. The lowest temperature ever registered in the 21st century was 8.1 °C (47 °F) in Vila Militar, July 2011. Temperatures below 10 °C (50 °F) are very rare in the city. The temperature varies according to elevation, distance from the coast, and type of vegetation. Winter brings mild temperatures and less rain than in the summer.

Average annual temperature of the sea is 23–24 °C (73–75 °F), from 22 °C (72 °F) in the period July–October to 26 °C (79 °F) in February and March. The wettest and driest months tend to be December and August respectively.