Malaysia’s equatorial climate means high temperatures and humidity year round and is characterized by two monsoon systems. The Southwest monsoon brings rain to the West Coast between May and September and the Northeast monsoon brings wet weather to the East Coast and the north of Borneo between November and February.
Rainfall during these times of year typically occurs in short sharp downpours, often late in the afternoon or early evening. September and October see the most rainfall on the West Coast.
The Northeast monsoon in general brings more rain than the Southwest, so bear this in mind if planning to visit the East Coast of Peninsula Malaysia during this time. Some resorts close during this period and there can be days of persistent rain.
The climate in Malaysian Borneo follows a similar pattern to the East Coast of Peninsula Malaysia, with most rain falling during the Northeast monsoon period between October and February.
Higher elevations in Malaysia can see cooler temperatures, meaning the Cameron Highlands can feel comparatively chilly in the evenings (15 degrees), with day time temperatures often in the low twenties. Of course climbing Mount Kinabalu in Borneo can mean sub-zero temperatures.