In the highlands, the weather can be very cold and temperatures frequently go below zero at night, especially on the Altiplano. Snow is common in Potosí during the winter months and sometimes also falls on La Paz and Oruro. In contrast, winter in Sucre, Cochabamba and Tarija on the Cordillera Real is a time of blue skies and comfortable temperatures.
The weather in the rainforest is usually very hot and is often very wet. The drier period of the year is May to October. The section of the rainforest that borders the Cordillera Real of the Andes Mountains is a bit cooler, but still very wet. As altitude declines, the temperature rises. Additionally many rivers and aquatic zones will dry up very noticeably in winter and then flood in summer creating an unpredictable landscape.