Uruguay: Weather Overview
Uruguay has a temperate climate with hot summers and mild winters. As it is quite close to the equator and almost surrounded by sea, Uruguay sees only small seasonal variations in temperature. Uruguay is bordered by Brazil to the north and Argentina to the west. The Pacific Ocean sits to its east and south. Sitting in the southern hemisphere, Uruguayâs seasons are the opposite of those in the northern hemisphere with winter falling from June till August. Uruguay is the second smallest country in South America and with low-lying, rolling topography and a long coast line, it experiences little regional variation in climate. These same factors also mean a lack of natural barriers to wind; wind blows freely across the country and so weather conditions are erratic, changing unpredictably.
Rainfall is evenly distributed throughout the year but the low, flat land and many rivers, including the Uruguay River which is the second longest on the continent, means the country is susceptible to flooding when there is a slight increase in rain. Rainfall is generally higher towards the Pacific. Along the rivers are a series of seasonal lakes.
Summer, from December till March, is hot and humid. The average high temperature in Montevideo climbs from 26°C in December to a peak of 28°C in January, getting back down to 25°C in March. Night times are much cooler, usually under 20°C, but can still feel very sticky. The blistering highs seen at similar latitudes just west of Uruguay are avoided due to the Pacific Ocean which stays quite cool even in the summer. The Pacific is warmest from January till March at 22°C. While temperatures are not extreme, the high humidity can often make it very uncomfortable, and cool sea breezes are often overridden by the zonda, a hot, northerly wind bringing tropical conditions from Brazil. Summer rain falls as tropical downpours: heavy and brief, sometimes causing floods. Sunshine levels are high, around nine hours per day, though it can get hazy due to the high humidity.
Autumn, in April and May, is warm with cool nights. The average high temperature reduces to 22°C in April and 19°C in May, which see average lows of 16°C and 13°C respectively. Sunshine reduces quite drastically to six hours per day in April and five in May, and fog coming inland from the sea and rivers is commonplace. Rainfall becomes less dramatic as the season progresses, shifting from the tropical summer storms to longer, lighter showers.
Winter, from June till August, is mild and damp. Snow is very rare; precipitation continues to fall in persistent drizzle from regularly overcast skies. This season is dominated by the pampero wind from the south which is cold and often very strong. This originates in Argentina which, stretching far south and with high mountains, can get very cold in wintertime. This wind makes the weather even more unpredictable from moment to moment. The sun still shines for around five hours each day, and the average high temperature does not fall below 15°C. The average low temperature, at night, gets down to 7°C in July and August. It tends not to get down to freezing so frosts are unlikely, though away from the coast it has been known to form. The sea gets down to 10°C in July and August.
Spring, from September till November, heats up quickly. The average high temperature climbs to 18°C in September, 20°C in October and 23°C in November. Night time temperatures remain cool, not rising above 15°C till mid November. The clouds begin to clear away and the sun shines for longer and longer, but fog develops quite regularly. Spring is still subject to the pampero wind which can suddenly force temperatures down
Uruguay is nicest in late spring/early summer and late summer/early autumn, when the temperature is still pleasantly hot but the worst of the humidity can be avoided. However, as said earlier, Uruguay is prone to very changeable weather; just when you think you've got the hang of things the wind can change causing large fluctuations in temperature and rainfall.
Global warming brought on the worst flooding Uruguay had seen in fifty years this January (2009), causing extensive damage and leaving almost 10,000 people homeless. A rise in sea level is also threatening coastal wetlands. Matters can only get worse as climate change progresses. While the country is certainly suffering at the hands of other countriesâ polluting industries, it is by no means an innocent bystander. Uruguayâs main environmental concerns are air and water pollution. High levels of pollution are created by the countryâs own industries. However, Brazilâs environmentally inefficient power plants are also a large cause for concern in Uruguay.
While Uruguay is an incredibly homogenous country with its temperate climate and flat landscape, there is great regional variation in terms of modern development and standard of living. The northern regions on the Brazilian border are the least developed which still have poor healthcare and education. Towards the coast contradictory conditions exist of high development but also high poverty. The departments of Montevideo and Maldonado are relatively affluent, modernised areas. Uruguayâs population is highly unevenly distributed, with over a third of the countryâs entire population living in the capital city.