(Bandar Seri Begawan, 30th) Brunei has entered the Southwest Monsoon season, which is expected to last until September. During this period, the weather will tend to be more stable with reduced thunderstorm activity, and the coming months may see drier-than-usual conditions.
The Brunei Darussalam Meteorological Department (BDMD) released a statement pointing out that compared to the inter-monsoon period, the atmosphere during the Southwest Monsoon is more stable, leading to relatively lower frequency of thunderstorms.
The department stated that during the peak of the Southwest Monsoon (usually falls in August), due to overall dry weather in Southeast Asia, Brunei may experience haze.
The Meteorological Department noted that the Southwest Monsoon also coincides with the active development period of tropical storms and typhoons in the Northwest Pacific and South China Sea. Although these systems typically form far from Brunei, their proximity and intensity may still affect local weather conditions.
The statement said these systems could trigger the formation of squall lines. Squall lines are fast-moving, narrow bands of thunderstorms that can bring unstable weather, including strong gusts and occasional thunderstorms.
According to climate records from the Brunei International Airport Meteorological Observation Station, the normal rainfall for June, July, and August is 237.7mm, 241.8mm, and 231.5mm respectively.
Climate model forecasts from international forecasting centers indicate that large-scale atmospheric conditions, particularly the El Niño–Southern Oscillation (ENSO), are expected to continue influencing regional weather patterns from June to August 2026.
The Meteorological Department stated that ENSO is expected to remain in the El Niño phase, with a probability of about 92%. The El Niño phenomenon typically results in reduced rainfall, higher temperatures, and lower relative humidity in Brunei.
According to long-term forecasts, June rainfall is expected to be slightly below normal; July rainfall is projected to be between 140 and 190mm, also slightly below normal; while August is expected to be even drier, with rainfall possibly dropping to 140mm or less.
The department stated it will continue to monitor weather changes and issue relevant alerts or warnings as necessary.
The department stated that during the peak of the Southwest Monsoon (usually falls in August), due to overall dry weather in Southeast Asia, Brunei may experience haze.
The Meteorological Department noted that the Southwest Monsoon also coincides with the active development period of tropical storms and typhoons in the Northwest Pacific and South China Sea. Although these systems typically form far from Brunei, their proximity and intensity may still affect local weather conditions.
The statement said these systems could trigger the formation of squall lines. Squall lines are fast-moving, narrow bands of thunderstorms that can bring unstable weather, including strong gusts and occasional thunderstorms.
According to climate records from the Brunei International Airport Meteorological Observation Station, the normal rainfall for June, July, and August is 237.7mm, 241.8mm, and 231.5mm respectively.
Climate model forecasts from international forecasting centers indicate that large-scale atmospheric conditions, particularly the El Niño–Southern Oscillation (ENSO), are expected to continue influencing regional weather patterns from June to August 2026.
The Meteorological Department stated that ENSO is expected to remain in the El Niño phase, with a probability of about 92%. The El Niño phenomenon typically results in reduced rainfall, higher temperatures, and lower relative humidity in Brunei.
According to long-term forecasts, June rainfall is expected to be slightly below normal; July rainfall is projected to be between 140 and 190mm, also slightly below normal; while August is expected to be even drier, with rainfall possibly dropping to 140mm or less.
The department stated it will continue to monitor weather changes and issue relevant alerts or warnings as necessary.