Haze threat looms over Singapore again after brief 3-day respite

Singapore has now enjoyed three days of better air quality , after a stretch of unhealthy-to-very unhealthy 24-hour Pollutant Standards Index (PSI) and high-to-very high hourly PM2.5, which began on Oct 5.

But, as the National Environment Agency (NEA) has been cautioning since Oct 18, winds could again turn — this time, not in the city state's favour.

In its daily haze situation update on Tuesday (Oct 20) night, the agency said that showers are forecast over Singapore and the surrounding region on Wednesday.

However, it cautioned that smoke haze from fires in Kalimantan may move towards Singapore as the winds are expected to blow from the east-southeast to southeast.

In updates on Sunday and Monday evening, NEA warned that this could happen from as early as Tuesday night.

In addition, dry conditions are likely to persist over southern parts of Kalimantan over the coming days.

"Under prevailing east-southeasterly to south-easterly winds, smoke haze may drift from fires in Kalimantan towards Singapore," NEA said, adding that Singapore's 24-hour PSI is forecast to be between 110 and 180 — in the unhealthy range.

At 8pm on Tuesday, hourly PM2.5 was in the normal band (0 to 55µg/m3) in northern (32), southern (46) and eastern (54) Singapore, but in the elevated band (56 to 150µg/m3) in the central (80) and western (93) regions.

Meanwhile, PSI is in the unhealthy range (101 to 200) in western (141), central (122), eastern (106) and southern (103) Singapore, with only the northern region registering a good-to-moderate reading of 85.

Members of the public are reminded to check the latest PM2.5 reading before participating in any outdoor activities.

新加坡在经历了从 10 月 5 日开始的 24 小时污染物标准指数 (PSI) 处于不健康到非常不健康水平，以及每小时 PM2.5 浓度处于高到非常高水平的时期后，已经连续三天空气质量有所改善。

但正如国家环境局 (NEA) 自 10 月 18 日以来一直警告的那样，风向可能会再次转变——这一次，风向可能对新加坡不利。

该机构在周二（10 月 20 日）晚间发布的每日雾霾情况更新中表示，预计周三新加坡及周边地区将有阵雨。

不过，该机构警告说，加里曼丹岛火灾产生的烟雾可能会向新加坡方向移动，因为预计风向将由东南偏东吹向东南。

新加坡国家环境局在周日和周一晚间的最新消息中警告称，这种情况最早可能在周二晚上发生。

此外，未来几天加里曼丹南部地区可能持续干旱。

“在盛行的东南偏东风至东南风的影响下，加里曼丹岛火灾产生的烟雾可能会飘向新加坡，”国家环境局表示，并补充说，新加坡24小时空气污染指数预计将在110至180之间——处于不健康范围内。

周二晚上 8 点，新加坡北部 (32)、南部 (46) 和东部 (54) 的 PM2.5 小时浓度处于正常范围 (0 至 55µg/m3)，但中部 (80) 和西部 (93) 地区的 PM2.5 小时浓度处于升高范围 (56 至 150µg/m3)。

与此同时，新加坡西部（141）、中部（122）、东部（106）和南部（103）的PSI指数均处于不健康范围（101至200），只有北部地区的PSI指数为85，属于良好至中等水平。

提醒公众在参加任何户外活动前，务必查看最新的PM2.5读数。