Like other rainforests, the Amazon Jungle lies on the equator and receives more sunlight than any other vegetation zone. The amount of water at this latitude combined with the amount of sun also means rainforests experience very wet weather, and the Amazon jungle is no exception.
There is a fairly predictable cycle in the Amazon Jungle where night time cooling causes morning mist. The mist is transformed to clouds with mid-morning convection, and in late afternoon, these become storm clouds creating the wet weather rainforests are known for.
In the Amazon Jungle, mountainous regions like western Amazonia experience the highest rainfall. Belem in far western Brazil has 2,438 mm (96 inches) of rain annually and, as a comparison, San Francisco experiences 561 mm (22 inches) with London having 595 mm (23 inches).
The geographical position of the Amazon Jungle means it receives a lot of sunlight creating a very hot and humid environment. As a rough guide to temperature, during daylight hours, the Amazon Rainforest gets up to around 33°C in early afternoon (the hottest time of day). In contrast, night time temperature can get down to around 18°C (64°F) so it is worth taking warm clothes for evenings. Interestingly, the marked temperature differences between day and night it greater than between months. In fact, there are no clearly distinguishable seasons in the Amazon Rainforest aside from the wet season and the dry season.
One of our most recommended Amazon Jungle Tours, the Tahuayo Lodge (northern Peru) has its wettest month in April with a 50% chance of afternoon showers compared to September, the driest month, where there is a 30% chance of showers. The busiest months here are March, June-August, and December holidays.
The wet and dry seasons create different probabilities for seeing different animals. During the dry season, pools of terrestrial water shrink concentrating the wildlife in certain areas. For example, if your interest is viewing anacondas, the best time to visit would be the dry season as there is less water for the snakes to hide. At the Heath River Wildlife Center and Tahuayo Lodge, the best time for anaconda viewing would be May to late in the year. For suggestions on what to do in the Amazon Rainforest, you can read our other article, which has detailed examples of activities and suggestions on tour companies catering to each option.
This giant anteater bathing in a rainforest pool was taken at the Tambopata Research Center, which is reached from Puerto Maldonado in southern Peru.
Given the unpredictable nature of animal spotting in the Amazon Rainforest, the wet season can mean more fruit is produced drawing different animals in search of a meal. The wet season can also mean otherwise inaccessible areas are flooded and easily navigated by canoe.
If you are investigating Amazon Jungle weather for a certain tour, the best option would be to contact the tour operator and ask direct questions, as the wet and dry seasons change for different areas and can mean different things depending on where you are going and what you are planning to do.
If you’ve visited the Amazon before, how did you find the weather? If you haven’t visited before, what time of year are you planning to travel and where are you going?