Inter-monsoon brings lighter winds and lower haze risk to Singapore
Meteorological Service Singapore says the onset of the inter-monsoon will shift winds to lighter, variable patterns and bring showers, reducing the likelihood of transboundary haze from Indonesian fires.
Singapore is expected to see a reduced risk of transboundary haze as the inter-monsoon season begins, with wind patterns shifting from persistent southeasterly or southwesterly flows to lighter, variable breezes, the Meteorological Service Singapore (MSS) said on Oct 29.
“With the shift from persistent southeasterly or southwesterly winds to light and variable winds in the surrounding region, smoke haze is less likely to be transported from fires towards Singapore,” MSS explained.
The agency added that wetter conditions over Singapore and neighboring areas will further suppress haze. The National Environment Agency forecast showers over Sumatra, Kalimantan, Singapore and the surrounding region on Oct 30, which should help keep haze levels low.
MSS’s fortnightly outlook projects moderate to heavy thundery showers in most parts of the island during the afternoons of the first two weeks of November, with occasional extensions into the evening. Total rainfall over that period is expected to be slightly above the long-term average, while daily high temperatures will remain between 33 °C and 35 °C, occasionally exceeding 35 °C.
Since Oct 26, Singapore’s 24-hour Pollutant Standards Index (PSI) has stayed in the good to moderate range, and PM2.5 levels have largely remained normal, with a brief rise to 57 in the west region on Oct 29 before dropping again.
Fires continue in Indonesia, with hot-spot maps from the ASEAN Specialized Meteorological Centre still showing activity in Kalimantan, though recent rainfall has reduced the number of active fires. The centre noted that areas receiving showers may see improvements, while regions experiencing prolonged dry weather could maintain elevated smoke levels.
The inter-monsoon follows the south-west monsoon that began in June and typically brings lighter winds and more frequent lightning. The current super El Niño has extended the dry south-west monsoon by about a month, but the inter-monsoon usually starts in early October.
Minister for Sustainability and the Environment Grace Fu previously said that the upcoming north-east monsoon, arriving in early December, will bring northerly winds that push any remaining haze away from Singapore.