Haze update Sept 30: Air quality improves after thundery showers, 24-hour PSI forecast moderate to low-unhealthy

Moderate to heavy thundery showers across the northern, western and central areas of Singapore on Wednesday (Sept 30) afternoon helped keep the haze at bay, with 24-hour Pollutant Standards Index (PSI) continuing to fall towards the moderate range.

At 6pm, the 24-hour PSI readings ranged from 91 in northern Singapore, to 112 in the central region. This is in the moderate to unhealthy range.

Meanwhile, the one-hour PM2.5 reading is between six and 18, in the normal band. Concentrations readings of between 0 to 55 denote the normal band.

In its daily haze situation update on Wednesday evening, the National Environment Agency (NEA) said the country's 24-hour PSI is forecast to be in the moderate to low-unhealthy range.

This is an improvement from the high-moderate to mid-unhealthy forecast a day earlier.

Smoke haze from southern Sumatra and Kalimantan was observed to have drifted towards Singapore, NEA noted.

Along with the prevailing south-easterly or southerly winds, the risk of smoke haze affecting Singapore remains, it added.

Members of the public are advised to check the one-hour PM2.5 concentration readings before participating in any immediate outdoor activities.

9 月 30 日（星期三）下午，新加坡北部、西部和中部地区出现中到大雷阵雨，有助于控制雾霾，24 小时污染物标准指数 (PSI) 继续下降至中等水平。

下午6点，新加坡北部24小时空气污染指数（PSI）为91，中部地区为112，属于中度至不健康范围。

同时，一小时PM2.5读数在6到18之间，属于正常范围。浓度读数在0到55之间均属于正常范围。

国家环境局（NEA）在周三晚间发布的每日雾霾情况更新中表示，该国24小时空气污染指数（PSI）预计将处于中度至轻度不健康范围。

这比前一天预测的高至中等至中等不健康状况有所改善。

新加坡国家环境局指出，来自苏门答腊南部和加里曼丹的烟雾已经飘向新加坡。

报告还指出，由于盛行东南风或南风，烟雾影响新加坡的风险依然存在。

建议公众在参加任何户外活动前，先查看一小时 PM2.5 浓度读数。