Observation

This question was attempted by very few candidates and the performance of those who attempted it was poor. The major groups of Koppen’s climates are:
A - rainy climates with no cold season
  B - dry climates
  C - rainy climates with mild winter (mesothermal)
  D - rainy climates with severe winters (microthermal)
  E - polar climates with no warm seasons
    
  The basis of Koppen’s Classification are temperature and precipitation.
  The types of Koppen’s first group of climates are:
  - Af:  Tropical Rainforest climate
  - Aw: Tropical grassland/savanna/continental climate
  - Am: Tropical monsoon climate.

The Unique features of the types of climate in Koppen’s first group of climate:
Af – Tropical rainforest climate
- high constant temperatures of about 27^oC throughout the year
- mean monthly temperatures of about 26^oC
- heavy rainfall between 1500mm and 3000mm
- rainfall is mainly convectional.
- rainfall distribution is throughout the year (no month without rainfall)
- rainfall is accompanied by thunder and lightening
- rainfall has double maxima
- high humidity of over 80% throughout the year
- double maxima coincides with the equinoxes
- range of temperature is low- about 3^oC
- found between latitudes 5^oN and 5^oS
- climate supports dense vegetation
- dense cloud cover
- mornings are mostly bright and sunny

Aw - Tropical continental/savannah climate:
- located between latitudes 10^o and 35^o north and south of the Equator
- high summer temperatures of about 32^oC
- lower winter temperatures of about 21^oC
- seasonal rainfall (dry and wet seasons)
- low annual rainfall of about 250mm - 1500mm
- annual range of temperature is 11 oC
- rainfall occurs in summer
- rainfall mainly convectional
- rainfall is single maximum
- winds are off-shore in winter and on-shore in summer
- relative lower humidity is low, and less than 60%
- reasonable cloud cover in the rainy season
- cloudless nights
- climate supports grassland vegetation
- hottest months are April in northern hemisphere and October in southern hemisphere
- best developed in West, East and Central Africa
Am - Tropical monsoon climate:
- high temperatures of about 21^oC - 27^oC
- annual temperature range is 7^oC
- three distinct seasons
- hot and dry season
- hot and wet season
- warm and dry season
- rainfall is heavy in wet season 2000mm-5000mm

- rainfall amount could be as high as  10,800mm in some areas
- rainfall duration is 4 months (mid-June-September/October)
- high relative humidity during wet seasons
- maximum rainfall occurs at the beginning of the rainy season
- rainfall is usually sudden and abrupt
- rainfall is mainly orographic
- supports varying vegetations from evergreen to thorny scrub
- in hot dry season, temperatures rise sharply
- temperature reaches average of 30^oC in May and can reach 43^oC
- heat is so much that schools and offices are closed
- in warm dry season, temperatures are low, about 10^oC  - 24^oC
- frosts may occur at nights on highlands
- dust storms are  common in dry seasons