1.0 What Is Climate?
Climate in a narrow sense is usually defined as the "average weather," or more rigorously, as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period is 30 years, as defined by the World Meteorological Organization (WMO). These quantities are most often surface variables such as temperature, precipitation, and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.
The climate system is the highly complex system consisting of five major components: the atmosphere, the hydrosphere, the cryosphere, the land surface and the biosphere, and the interactions between them. The climate system evolves in time under the influence of its own internal dynamics and because of external forces such as volcanic eruptions, solar variations and human-induced forces such as the changing composition of the atmosphere and land use change.
2.0 Malaysia's Climate
The characteristic features of the climate of Malaysia are uniform temperature, high humidity and copious rainfall. Winds are generally light. Situated in the equatorial doldrum area, it is extremely rare to have a full day with completely clear sky even during the periods of severe drought. On the other hand, it is also rare to have a stretch of a few days with completely no sunshine except during the northeast monsoon seasons.
Though the wind over the country is generally light and variable, there are, however, some uniform periodic changes in the wind flow patterns. Based on these changes, four seasons can be distinguished, namely, the northeast monsoon (Figure 1), southwest monsoon (Figure 2), and two shorter periods inter-monsoon seasons (Figure 3).