HKDSE Geography/M6/Climate

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Most tropical rainforests have tropical maritime climate or equatorial climate. The properties are discussed below.

In this page, we discuss only the general climate of rainforests. Rainforests have a set of distinct microclimates within them, and we will discuss this later.

Insolation and Temperature[edit]

Tropical rainforests have the following climatic characteristics:

  • Intense insolation, at least 10 hours a day
    • Because they are located in equatorial regions
  • High annual mean temperature: 26°C
    • Because they are located in equatorial regions
  • Small diurnal range of temperature - 7-8°C
    • Because the dense cloud cover produces a blanket effect
  • Small annual range of temperature - 2-4°C
    • Because of the small annual range of insolation in equatorial areas
      • Result: Lack of seasonality - no distinct winter

As a result of high insolation, evapotranspiration rate is also high.

Detailed explanations for the above patterns can be found in M7 and E2.


Tropical rainforests have the following rainfall patterns:

  • High annual rainfall, above 2000m, and exceeds evapotranspiration
  • Lack of seasonal patterns in rainfall, rainfall is evenly distributed throughout the year
    • Result: Lack of seasonality - no dry season
    • Exception: In tropical monsoon regions, there is more rainfall in summer.

Rain usually occurs as showers or thunderstorms.

Relative Humidity[edit]

Tropical rainforests have high relative humidity. We will look at exact numbers in the microclimate section.


Wind is generally weak in tropical rainforests because of the dense vegetation cover.

  • Exception: In monsoon areas, onshore and offshore monsoon winds are frequent.