Singapore Haze: PSI Enters the Unhealthy Range on 4 September, the First Time Since 2023

*Verified on 4 September 2026 against NEA's live readings (the 12pm 24-hour PSI pulled from NEA's real-time air quality data), NEA's haze situation update and outlook posted at 11.13am on haze.gov.sg, NEA's official health advisory poster "How to Plan Your Outdoor Activities During Haze" (July 2024), MOH's haze page, and MOH's Haze Subsidy Scheme page on HealthHub, and NEA's Haze Task Force media release of 4 September 2026. Regional 8am figures and the "first since October 2023" comparison are as reported by AsiaOne.*

> Quick view: Central Singapore's 24-hour PSI hit 103 at 8am on Friday 4 September 2026 and 105 by noon, crossing into the Unhealthy band (101 to 200) for the first time since October 2023. The other four regions are still Moderate. At this level NEA asks healthy people to do less prolonged or strenuous outdoor exertion, children and the elderly to do as little as possible, and people with chronic lung or heart disease to not do it at all. An N95 is not what MOH recommends at 105. The Haze Subsidy Scheme is not currently open. NEA begins daily haze advisories from this evening, and CC air-conditioned respite rooms open only if the PSI crosses 200.

Where things stand

NEA's live readings at 12pm on 4 September 2026:

At 8am the central figure was 103, with west 88, east 87, north 77 and south 75, so the trend through the morning was upward rather than settling. The 1-hour PM2.5 concentration at 8am was in the Elevated band in two regions, 64 µg/m³ in the central region and 57 µg/m³ in the east, and within the normal band elsewhere.

The source of it is regional and familiar. NEA's 11.13am situation update reports clusters of scattered hotspots in the central and southern parts of Sumatra and in West and Central Kalimantan, with moderate to dense smoke haze over most of Borneo, parts of Sumatra and southern Peninsular Malaysia. Air quality stations in West Kalimantan, Central Kalimantan, southern Sumatra and western Sarawak are reporting Unhealthy to Hazardous levels, which is a reminder that Singapore is getting the thin edge of this.

NEA's outlook for the coming days: dry conditions are expected to prevail over many parts of the southern ASEAN region, the hotspot and haze situation is expected to remain escalated where the dry spell persists, with a continued risk of severe transboundary haze, and the prevailing winds are forecast to blow from the southeast or south. While the 24-hour PSI stays in the Unhealthy range, NEA issues a daily haze advisory so you can plan the next day.

What "Unhealthy" actually asks you to do

This is NEA's own health advisory table for the 24-hour PSI forecast, the Unhealthy column only:

The value of that table is in NEA's own definitions, which most write-ups leave out. REDUCE means *do less*. MINIMISE means *do as little as possible*. AVOID means *do not do*. PROLONGED means continuous exposure for several hours, and STRENUOUS means an activity involving a lot of energy or effort.

Read that way, the advisory is narrower than it sounds. Nothing in it asks a healthy adult to stay indoors at PSI 105. What it asks is that you cut the long, hard, outdoor stuff: the 10km run, the full football session, an afternoon of gardening. Walking to lunch is not what this table is about.

Which number to use, and when

Two different readings do two different jobs, and using the wrong one is the most common mistake during a haze week.

• Planning something for tomorrow? Use the 24-hour PSI forecast and the table above. That is the number the government itself uses for major decisions.
• Deciding whether to go out in the next hour? Use the 1-hour PM2.5 reading, which reflects the air right now rather than the last 24 hours. NEA's bands are Normal (0 to 55 µg/m³), Elevated (56 to 150), High (151 to 250) and Very High (251 and above).

In the Elevated band, where the central and eastern regions sat at 8am, NEA's advice is to reduce strenuous outdoor activity for the next hour, and for vulnerable persons to avoid strenuous outdoor activity for the next hour. NEA defines vulnerable persons as the elderly, pregnant women, children, and people with chronic lung disease or heart disease.

Masks: less than you would expect at this level

MOH's position is more restrained than the shopping behaviour a haze headline usually triggers.

• N95 masks are generally not needed for short-term exposure such as commuting.
• Healthy people who need to be outdoors for several hours may reduce their exposure with an N95 when air quality is in the hazardous range, above PSI 300. Central Singapore is at 105.
• Elderly people, pregnant women and people with severe lung or heart problems should consult their own doctor about whether to use an N95 if they must be outdoors for several hours.
• Anyone who is unwell, especially the elderly and children, and anyone with a chronic heart or lung condition, should seek medical advice rather than self-manage.

Worth adding: surgical and cloth masks do not filter PM2.5, so they are not haze protection. An N95 works only when it seals against the face, which is why it does not work well on children.

The subsidy scheme, and why it is not open today

The Haze Subsidy Scheme is the piece most readers ask about, and the honest answer on 4 September is that it is not running. MOH's HealthHub page states that the scheme is not being offered until further notice. Nothing about today's reading changes that by itself.

Because activation can happen quickly, here is the shape of it. When MOH turns it on, it applies at all polyclinics and Public Health Preparedness Clinics (PHPCs), which put up signage. For a consultation the doctor assesses as haze-related, the capped payment is:

GST is not charged on those amounts. Covered conditions are allergic rhinitis, asthma, bronchitis, conjunctivitis, chronic obstructive pulmonary disease, upper respiratory tract infections and their complications.

What would have to change for the big decisions

NEA's poster is explicit about how the escalation ladder works: the Government uses the 24-hour PSI forecast to implement its action plans, to guide risk assessment of immediate activities, and to advise major decisions such as school closure and the suspension of training or outdoor work. So the trigger for the announcements people are watching for is the forecast, not a single hourly spike, and it comes from the agencies rather than from any reading you can look up yourself.

What the Haze Task Force announced on 4 September

NEA issued a joint statement on the afternoon of 4 September on behalf of the 28 agencies in the Government's Haze Task Force. Three things in it change what a reader should actually do.

Daily haze advisories start this evening. NEA will begin issuing a daily haze advisory from the evening of 4 September 2026, and each one will carry the 24-hour PSI forecast. That is the number the Government itself uses to plan, and it is now published once a day rather than left to you to infer from live readings.

Air-conditioned respite rooms, but only above PSI 200. Air-conditioned rooms in all Community Centres/Clubs (CCs) and selected Residents' Committee (RC) and Residents' Network (RN) Centres will be on standby for members of the public who want respite from the haze. The trigger is the 24-hour PSI crossing into Very Unhealthy, above 200. Central Singapore is at 105 today, so this is a contingency rather than something open right now. Residents can contact their nearest CC or check RC/RN notice boards for the locations.

Schools stay open and national examinations proceed as scheduled. MOE states that all classrooms in primary and secondary schools, junior colleges and Millennia Institute, MOE Kindergartens and Special Education schools are equipped with air purifiers. If air quality is in the Unhealthy range or worse during an examination, candidates will sit their papers in enclosed spaces with air purifiers. Only a school closure would reschedule national examinations, and candidates would be told through their schools, or through SEAB if they are private candidates. Preschools are also equipped with air purifiers, with at least one enclosed room with purifiers running to hold any child who becomes unwell.

Two smaller points worth knowing. MOM is urging all workplaces at the Unhealthy level to shorten prolonged or strenuous work, minimise it for elderly and pregnant workers, avoid it for workers with chronic heart or lung conditions, and use job rotation, indoor rest breaks, hydration and suitable protective equipment. LTA is asking motorists to switch on headlights when visibility is low.

Practical things worth doing today

• Move the workout indoors or shorten it. That single change satisfies most of the advisory for a healthy adult.
• Keep windows shut on the windward side and run an air purifier if you have one. Our air purifier guide covers what actually filters PM2.5.
• Check reliever medication for anyone in the household with asthma or COPD, before the weekend rather than during it.
• Check the 1-hour PM2.5 before you head out, not the number you saw this morning.
• Where to look: haze.gov.sg for live readings and the daily advisory, or the myENV app on your phone.

This article summarises published NEA and MOH guidance. It is not medical advice. If you or someone in your household is unwell, see a doctor, and confirm scheme status and any school or workplace arrangements with the relevant agency.

Related

• Singapore Haze Watch (August 2026): the background piece from when the PSI was still climbing through the Moderate band
• Best Air Purifiers in Singapore 2026: what to buy if you are finally getting one
• Best Singapore Promos and Deals This Month: the full running roundup

*Readings and advisories as published by the National Environment Agency and the Ministry of Health, read on 4 September 2026. PSI readings move hourly. Check haze.gov.sg or myENV for the current figure before acting on anything here. Cover image: NEA's official health advisory poster, "How to Plan Your Outdoor Activities During Haze".*