WEATHER AND CLIMATE IN MALAYSIA
Colonialists at the Residency at Larut, near Taiping, in a sketch from The Graphic, titled 'At the Residency Larut: A Wet Day'.
In Malaysia, where temperatures are generally high and show little variation during the course of the year, it is not possible to differentiate between summer and winter as in temperate regions. Neither is it feasible to divide the year into wet and dry seasons as heavy rainfall may occur anywhere and at any time of the year. Although relatively short, dry spells may be experienced in a particular year, these are not sufficiently long and regular in their occurrence to justify being called 'dry' seasons. Nevertheless, the climate of this region does have a seasonal rhythm which is controlled largely by the synoptic wind system which is dominated by the monsoon. The latter, together with local and regional disturbances and topographical features, determines the general pattern of the wind seasons which, as over most parts of Southeast Asia, are reflected in the rainfall patterns.
The monsoon represents a significant change in wind direction and humidity associated with widespread temperature changes over land and water. The monsoon is caused by a combination of factors: the differential effects of heating and cooling of the Siberian landmasses and the surrounding seas, the northward movement of the Inter-Tropical Convergence Zone (ITCZ) (where the trade winds meet) during the northern summer, and the interference to the atmospheric circulation caused by the Himalayan mountains.
There are four recognizable seasons in Malaysia during the course of a year. The northeast monsoon lasts from November or early December until March and the southwest monsoon from June until September or early October. There are two intermonsoon seasons that operate, respectively, from April to May and from October to November. In Peninsular Malaysia, the northeast monsoon normally brings heavy rain and the southwest monsoon season is relatively dry, especially during June and July. From August until the end of the season, the monthly rainfall at most places shows a steady increase. These characteristics describe the average climatic conditions that are likely to be experienced in any one year in Malaysia. These features do, however, vary from year to year depending on the broader scale circulation of air currents in the atmosphere and currents in the seas. Local-scale effects on the climate include the haze, which brings smog to the region, and the periodic El Niño phenomenon. The latter has been identified as the cause of major climate extremes. In Malaysia, extremely high temperatures and all-time rainfall lows were recorded in 1983 and 1998 coinciding with El Niño events.
Malaysia has high temperatures and ample sunshine the whole year. However, due to varying weather conditions, the actual amount of radiation received varies from day to day, putting a limitation on the industrial application of solar energy, but progress has been made to harness it for domestic purposes and in rural areas.