Rio de Janeiro climate
Rio has a tropical savannah climate (Aw ) that closely borders a tropical monsoon climate (Am ) 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 frost in its past, but it was never confirmed. Some areas within Rio de Janeiro state have snow grains and ice pellets with an even frequency (popularly called granizo, or “hail”, although it is in fact melted and refrozen snow falling in the form of a ball—true hail, rather than just icy snow along showers, is much less common). These phenomena are definitely not rare or limited to a few regions, happening in the metropolitan area (including western suburbs of the city itself) at least three times in the 21st century, said to be approximately each two decades or less in some regions. In other areas there is true snowfall more than once in each century, most commonly around the highest mountain in the state (for perhaps centuries thought to be the country’s) and fifth in the country, Pico das Agulhas Negras, in the cities of Resende and Itatiaia (in lower latitudes than Rio de Janeiro, but much higher altitudes).
Roughly in the same suburbs corresponding to the March 2012 and February–March 2013 granizo falls (Nova Iguaçu and surrounding areas, including parts of Campo Grande and Bangu), there was a tornado-like phenomenon in January 2011, for the first time in the region’s recorded history, causing structural damage and lasting blackouts, but no fatalities. The World Meteorological Organization alerts Brazil, specially its Southeastern region, that events as the catastrophic January 2011 Rio de Janeiro floods and mudslides are not an isolated phenomenon and that Brazil must be prepared for severe weather in the next years. “This (the early 2010s serial devastation in Rio de Janeiro’s mesoregions Metropolitana do Rio de Janeiro and Sul Fluminense) was not an isolated event. The events in Brazil confirms a global trend that storms tend to be increasingly strong and in places where it did not take place with the same force”, said Rupakumar Kolli, WMO expert on climatological phenomena.In early May 2013, winds registering above 90 km/h (56 mph) also caused lasting blackouts in 15 neighborhoods of the city and three surrounding municipalities, and it killed a person.
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 (46.3 in). According to INMET, the minimum temperature recorded was 4.8 °C (40.6 °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 (46.6 °F) in Vila Militar, July 2011. Rio de Janeiro lags only after Cuiabá at being the hottest state capital outside Northern and Northeastern Brazil; temperatures below 14 °C (57 °F) happen in a yearly and those below than 11 °C (52 °F) happen in a less than yearly basis, so fazer frio (“making cold” i.e. “weather is getting cold”) usually intends for temperatures below 21 °C (70 °F), present in a seasonally basis year-round and commonplace in mid-to-late autumn, winter and early spring nights.
Temperature also varies according to elevation, distance from the coast, and type of vegetation or land use. Winter, cold fronts and dawn/morning sea breezes bring mild temperatures; cold fronts, the Intertropical Convergence Zone (in the form of winds from the Amazon Forest), the strongest sea-borne winds (often from an extratropical cyclone) and summer evapotranspiration bring showers or storms. Thus the monsoon-like climate has dry and mild winters and springs, and very wet and warm summers and autumns. As a result, temperatures over 40 °C (104 °F), that may happen about year-round but are much more common during the summer, often mean the actual temperature feeling is over 50 °C (122 °F), when there is little wind and the relative humidity percentage is high. In such weather, avoiding dehydration (by high consumption of water, and if possibly potassium in people not affected by hyperkalemia, and low consumption of sodium), over-exercising and direct exposure to the sun is recommended, especially for children and elders.
There is also a slightly greater seasonal difference in the incidence of solar radiation people receive in Rio de Janeiro (or about anywhere else in the Southern Hemisphere) in comparison to places in the Northern Hemisphere with similar climate and the same exact latitude as the Earth most closely approaches Sol (the local Sun) only 12 days after the Southern Hemisphere’s summer solstice. See illustration at Season#Customary timing.
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 dominant ocean current is the warm Brazil Current (as most of elsewhere in the Santos Bight between Santa Catarina and Cabo Frio; the subsurface part of the cold subantarctic Malvinas Current only slightly resurfaces to affect the latter, giving the characteristic semi-arid climate in parts of Arraial do Cabo, the only occurrence of such in the whole state). The wettest and driest months tend to be December and August respectively.
Friday, August 5
The 2016 Rio Olympic Games 2016