The hot weather due to the El Nino phenomenon which is currently sweeping the country is expected to return to normal by the end of May, according to the Malaysian Meteorological Department's National Geophysics and Weather Operations Centre meteorologist Khairul Najib Ibrahim.

He said this was following the damp weather conditions with rain and thunderstorms occurring in the afternoon in most areas of the country, which is expected to gradually reduce the effects of the phenomenon.

"This condition (wet weather) involves a number of areas including the West coast of the peninsula, the western and central parts of Sarawak, and several divisions in Sabah.

"This comes as the country is undergoing a transitional monsoon phase where the prevailing winds are usually weak and bring rain with thunderstorms in the late evenings, and sometimes extends until early next morning, especially on the West coast of the peninsula," he said when contacted by Bernama here today.

El Nino occurs when the water surface temperatures in the central and eastern tropical Pacific Ocean rises considerably higher than average, leading to changes in air circulation patterns.

The phenomenon which has lasted since February, has also resulted in a number of states experiencing water supply problems as the water levels in several major dams have decreased.

However, Khairul Najib said the heat wave status for Peninsular Malaysia as of yesterday (26 April) still showed relatively high temperatures recorded in the northern and central regions of the Peninsula, as well as the interiors of Sabah and Sarawak.

"Maximum temperaturse of between 35 and 37 degrees Celsius was reported to have occurred in several areas including Gua Musang in Kelantan, Jerantut in Pahang, Jempol in Negeri Sembilan, as well as Mersing and Segamat in Johor.

"The temperatures in Sabah and Sarawak are still at normal levels, except in a few areas, namely Kota Marudu, Tongod and Beluran in Sabah, and Limbang in Sarawak," he said.

Meanwhile, the hot and dry weather also caused a decline in water levels involving several dams in Johor, namely Sungai Lebam in Kota Tinggi, Congok and Mersing and Sungai Layang Masai in Johor Baharu.

National Water Services Commission (SPAN) Resource Management and Engineering deputy director Khithob Ahmad said the drop in water levels was caused by the prolonged hot weather in the country.

"Rain only occurs in several areas in Johor, but rarely in catchment areas.

"Accordingly, SPAN will continue monitoring with water supply operators in the country to ensure there is sufficient water supply. We will also try to find solutions to overcome the water supply problem during the dry season," he said.

However, he said in the event of water shortage, SPAN will regulate the water supply in the affected areas.