The Amazon rainforest is an ecosystem spanning nine South American countries, known for its immense biological diversity and consistently high humidity. Because of its location straddling the equator, the region receives intense solar radiation throughout the year. However, this tropical environment maintains a relatively stable, warm climate year-round, and its temperatures rarely reach the extremes found in other biomes. The forest’s unique biophysical processes prevent its internal air temperatures from soaring to the levels seen in arid regions.
The Highest Officially Recorded Air Temperature
The highest official air temperature recorded within the Amazon basin reached approximately 41°C (105.8°F) in 2023, during a severe drought and heatwave in Brazil. This temperature was registered in non-forested or highly affected areas of the basin, not the dense jungle interior. Historically, localized measurements near the transitional boundary, such as the Chaco Amazon district in Bolivia, have cited peaks as high as 47°C (116.6°F). However, the central, intact rainforest typically experiences daily maximums that hover between 32°C and 35°C (90°F to 95°F).
How the Rainforest Canopy Regulates Heat
The Amazon’s dense, multi-layered canopy acts as a natural air conditioner, preventing extreme heat from developing on the forest floor. This thick layer of foliage intercepts up to 95% of incoming solar radiation, shading the air below and maintaining a relatively cool, stable microclimate. The primary cooling mechanism is a process called evapotranspiration, often described as the “forest sweating.”
This process involves the transfer of water vapor from the leaves and the forest floor into the atmosphere. When solar energy strikes the forest, a large portion of that energy is used to change liquid water into vapor, which absorbs heat (latent heat flux). This conversion effectively cools the surrounding air, keeping the forest’s temperature lower than it would be otherwise. If the forest cover is removed, the solar energy is instead converted into sensible heat, which directly warms the air and leads to temperature increases. The high humidity resulting from this constant water cycling further limits temperature increases.
Comparison to Global Temperature Extremes
The Amazon basin’s maximum recorded temperatures are significantly lower than those found in arid or semi-arid regions globally. For instance, the highest officially registered air temperature on Earth is 56.7°C (134°F), recorded in Death Valley, California. Tropical deserts can routinely reach temperatures exceeding 45°C (113°F) because they lack the moisture needed for evaporative cooling. The Amazon’s water-heavy environment makes a difference in how heat is managed.
In a desert, the absence of water means nearly all incoming solar energy is converted into sensible heat, raising the ambient air temperature. In contrast, the Amazon’s continuous cycle of evaporation and transpiration uses up much of the heat energy, converting it into latent heat stored in water vapor. This explains why the Amazon, despite its equatorial latitude, is thermally mild compared to other regions. The high humidity effectively caps the temperature ceiling of the rainforest.
Long-Term Trends in Amazonian Heat
While the Amazon has historically maintained a stable thermal environment, long-term data indicates that the frequency and duration of extreme heat events are increasing. This change is driven by the combined pressures of global climate change and localized deforestation. Forest loss breaks the evapotranspiration cycle, leading to a rise in sensible heat and a corresponding increase in local air temperatures. Scientists have observed that areas with high rates of deforestation experience significantly higher warming compared to intact forest areas, sometimes by as much as 4.4°C, creating localized “hot spots.” This increasing heat stress jeopardizes the forest’s ability to store carbon and raises the risk of tree die-offs, suggesting new temperature records are increasingly likely in the coming decades.