Being one of the two land-locked countries in the continent, Bolivia climate experiences a wide variation, from tropical weather in the lowlands to polar, high up in the Andes mountains.
With little seasonal variation, temperatures are mainly determined by altitude. Summer month (Dec to March) are the rainiest, while winters (June to August) are very dry, which makes it the best time of the year to discover the country.
Winter in the Altiplano means extreme heat during the day, and freezing winds and subzero temperatures at night, so it is suitable to wear summer as well as warmer clothes and to dress in layers to quickly adjust to changing conditions. Include a rain jacket as well.
Changes in temperatures and weather in Bolivia are typically as abrupt as the changes in topography for any given region.
Bolivia’s two poles of climatic extremes occur in Uyuni salt flats, with its icy winds and in Puerto Suarez with its scorching heat - maximum registered 47°C - however, there are not absolutes, Bolivia weather is so unpredictable that the opposite could also be true!
In case you get a bit confused with Celsius degrees, here is a quick conversion chart from Celsius to Fahrenheit.
Temp/Precip Graph for La Paz, Santa Cruz and Cochabamba - Source: Food and Agricultural Organization
Bolivia climate in the Northern lowlands have a tropical wet climate with high humidity, lots of rain and consistent daily temperatures over 30° C throughout the year, while the central lowlands have a tropical wet and dry climate.
With semitropical and semiarid climate, the Chaco region becomes hot, rainy and humid during summer month, with hot days and cool nights the rest of the year. With temperate and sub-tropical climate, the Yungas - North-eastern flank of the Cordillera Real - is the rainiest and most humid of all, with with an average temperature of 24°C. Its names comes from Aymara language, meaning "warm valleys."
The Puna and Altiplano regions is swept by cold winds, with chilly climate and sharp differences in daily temperature. While average highs during the day range from 15° C to 20° C - it may exceed 27° C in summer month, at nightfall temperatures rapidly drop to the freezing line. Above the 4.000 meter mark it may get down to -25°C at night in June-August.
In practical terms, think about Bolivia climate as locals do, consisting of only two seasons - the wet season and the dry season. May to September is your best bet to discover the country, as road conditions deteriorate, landslides may occur and river swell during summer month, up to the point that some roads may become inaccessible.
For official info regarding weather in Bolivia, please visit www.senamhi.gob.bo - site in Spanish.