Malaysia is a tropical country, very much like most of the countries located in Southeast Asia. The temperature can be hot throughout the year and there is a large amount of rainfall. Let me provide you a brief description of Malaysian weather and climate in the next few paragraphs.
Temperature
Just like any other tropical country, the temperature in Malaysia remains regularly hot throughout the year. There is no considerable difference between seasons, like summer and winter. Days are warm and usually humid but the nights are quite cool. The temperature also varies in different locations. At Penang, the temperatures stay close to 82F (28 C) and at Labuan the average temperature is 80F (27 C). The temperature in areas located above sea level is considerably cooler. The Cameron Highlands which are about 5000 feet (1500m) above sea level has a temperature of 64F (18 C) which is very much a good thing for foreigners.
Rainfall
The main raining season runs between Nov. and Feb. , while Aug. is considered the most humid and wettest period on the West Coast (Terengganu, Kelantan and Pahang). Sabah and Sarawak have heavy rains during November to February. Rainfall, however, is heavy all year round in the country. Rainfall is heavy in the mountain areas. In the Cameroon highlands, the total annual rainfall is over 100 inches (2540 mm). No single month has less than 5 inches or 125 mm of rainfall. If you are planning on visiting a country it is important to consider the rainy months. June through August is considered the best time to visit Malaysia; this is the time when rainfall is not heavy and the temperature not so hot at only 64F or 18C.
Malaysia is a tropical country with warm weather and humid climate. Rainfall is also abundant. It is rewarding though to visit the highlands for their lush greenery.