The Climate of Brunei

Brunei Darussalam is a small country situated around 4 degrees north of the Equator and around 114 degrees east, just next to the East Malaysian state of Sarawak. The country has an equatorial type of climate with high temperatures and rainfall all year round.

Northeast monsoon winds blow from Dec- Mar while the southwest monsoon occurs from May-Sep. April and Oct are the transition months between the monsoons, characterised by light and variable winds.
 
There are also two types of diurnal wi nd systems - the land and sea breezes along the coast and the katabatic and anabatic wind further south. The weather in Brunei is determined by the combination of these local winds and the larger scale monsoon winds. Ocasionally, tropical cyclones in the South China Sea, although not directly affecting the country, may also contribute to the local weather pattern eg by affecting wind strength and direction or slightly more unsettled weather. Rainfall in Brunei is heavy and usually occurs in the form of thunderstorms. Rain is abundant and occurs all year round.

Temperatures differ little from month to month, and there is no large daily range of temperature. Night-time temperatures can be oppressive due to high humidity. Although the climate is warm and humid, severe heat stress is rare. The transition months (April & Oct) can be uncomfortable because winds are light and humidity may be higher. In the afternoons, conditions on the coast are often relieved by sea breezes.

	Bandar Seri Begawan Month Rainfall(mm) Temperature (Celsius) Ave. Monthly Ave. No. of Days with 1mm Average Daily Lowest Recorded Highest Recorded Min Max Jan 308 15 23 30.2 18.4 33.9 Feb 158 10 22.9 30.6 18.9 35.3 Mar 129 9 23.1 31.6 19.4 38.3 Apr 177 12 23.4 32.3 20.5 37.6 May 228 15 23.4 32.4 20.3 36.4 Jun 201 13 23.0 32.4 19.2 35.5 Jul 219 13 22.6 32.1 19.1 35.7 Aug 198 12 22.7 32.3 19.4 36.6 Sep 285 16 22.8 31.9 19.6 35.5 Oct 304 18 22.9 31.6 20.5 34.7 Nov 359 20 22.9 31.3 18.8 34.5 Dec 343 18 22.9 30.9 19.5 36.2