Like Montevideo, average temperatures of Lima fall within a limited range year round. Perhaps the most striking difference illustrated by the two images below concerns the sporadic wind directions throughout Uruguay compared to the steady winds from the South in Lima.
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| Weather data for Lima from 2010 to 2011. From http://myifrugeog3232.blogspot.com/ |
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| Weather data from Montevideo for the same date range. www.wunderground.com |
This steady wind from the South is related to Lima's proximity to the intertropical convergence zone and the influence generated by the trade winds.
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| Note the direction of the winds near the doldrums relative to the approximate location of Lima. Idealized global circulation, © Prentice Hall, Earth Science 11th ed with modifications |
Both locations enjoy subtropical environments influenced by the nearby ocean however the flat topography of Montevideo contrasts to the Andes mountains in Peru. While precipitation in Montevideo is consistent year round, the Andes create a barrier that can create seasonal changes in precipitation.
Both Lima and Montevideo experience weather due to maritime air masses, Lima is primarily influenced by polar air while Montevideo enjoys tropical air. The major current off the coast of Lima is the cold water Peru current, much colder than the Brasil Current off the coast of Montevideo [1].
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| http://www-odp.tamu.edu/publications/201_SR/122/122_f3.htm with modifications |
Note the average annual sea surface temperatures of the coast of Peru are slightly colder than Uruguay:
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| Though at first it may seem the east coast of the continent is also surrounded by dark blue, note the warmer sky blue in the inlet by Montevideo, closest to the continent. http://forces.si.edu/elnino/01_00_00abc.html |
Because of the cold water Peru current and large land mass that separates Lima from the Atlantic Ocean, tropical cyclones are not a severe weather issue that affect Lima. Likewise Uruguay is separated from the rest of the warm Atlantic Ocean by cold water currents to the east of the Brasil current. Montevideo is also south of the circulating high pressure system that directs tropical storms and hurricanes to the north so these types of storms are rare in Uruguay.
Tornadoes are fairly rare occurances in both Lima and Montevideo. Occasionally, conditions conducive to tornadic activity in Brazil to the north of Uruguay can travel south and affect areas near Montevideo. The Andes mountains near Lima typically protect the region by disrupting conditions that cause tornadoes. [2]
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