烟霾周日夜里短时冲高：全岛一度进入不健康范围，中区读数峰值达136
新加坡——烟霾在10月4日星期日夜里出现一次短时冲高：当晚9时至午夜之间，全岛各区空气一度全部进入不健康范围，中区读数峰值达到136。这是新加坡这一轮烟霾中值得记录的又一个节点——白天各区读数仍在73至96之间徘徊，入夜后随着风向与烟羽位置变化，污染水平快速上升。
回顾这一周的轨迹：10月1日24小时PSI还在60至73之间，1小时PM2.5只有17至32微克/立方米；10月2日升至63至79；10月3日中区率先跨入不健康（105）；10月4日白天回落到73至96，夜里又冲到全岛不健康。国家环境局此前在周五晚的提示中已预警：苏门答腊南部的中到浓密烟羽在东南风下会持续向新加坡漂移，加里曼丹的烟霾也同时存在。
环境局指出，新加坡及周边地区的干燥天气预计持续，苏门答腊南部和加里曼丹的火点难以在短期内熄灭。这意味着，只要风向维持东南或东南偏东，海峡对岸的烟就会继续飘来；24小时PSI的预报区间为“高适中到中度不健康”。
本周新加坡将接连迎来大型会议周与一级方程式新加坡大奖赛周末（10月9日至11日），数以万计的访客将进行大量户外活动。国际汽联（FIA）本周表示正与本地当局密切监测空气质量。烟霾的每日变化，将通过环境局的haze.gov.sg专题页和myENV应用持续发布。
来源：据Batam News Asia引述《海峡时报》与国家环境局读数的报道、Travel and Tour World汇总的环境局逐日数据整理。
Haze Spikes Briefly on Sunday Night: Whole Island Tips into Unhealthy Range, Central Reading Peaks at 136
SINGAPORE — The haze produced a brief night-time spike on Sunday, October 4: between 9 p.m. and midnight, air across the whole island tipped into the unhealthy range, with the central region peaking at a reading of 136. Daytime readings had hovered between 73 and 96. The night surge, driven by shifting winds and the position of the smoke plume, marks another notable point in this haze episode.
The week's trajectory tells the story: on October 1 the 24-hour PSI stood between 60 and 73, with 1-hour PM2.5 at just 17–32 micrograms per cubic metre; on October 2 it rose to 63–79; on October 3 the central region crossed into unhealthy territory at 105; on October 4 it eased back to 73–96 by day, then spiked island-wide at night. The National Environment Agency (NEA) had warned in its Friday-evening advisory that moderate to dense smoke plumes from southern Sumatra would keep drifting towards Singapore on southeasterly winds, alongside haze from Kalimantan fires.
The NEA said dry conditions were expected to persist over Singapore and the surrounding region, and the hotspots in southern Sumatra and Kalimantan would not be extinguished quickly. As long as winds stay from the southeast or east-southeast, smoke from across the strait will keep arriving; the forecast 24-hour PSI sits in the high-moderate to mid-unhealthy range.
This week brings a dense run of conferences and the Formula 1 Singapore Grand Prix weekend (October 9–11), with tens of thousands of visitors spending long hours outdoors. The FIA said this week it is monitoring air quality closely with local authorities. Daily haze changes will continue to be published on the NEA's haze.gov.sg microsite and the myENV app.
Sources: Compiled from Batam News Asia's report citing The Straits Times and NEA readings, and Travel and Tour World's compilation of the NEA's daily figures.
图片来源：图：烟霾笼罩下的新加坡市中心天际线（资料图）。摄影：SpLoT，CC BY 2.5，来源：Wikimedia Commons
