Haze in Singapore 2026: what it does to you, and when to see a doctor

Where things stand

As of 24 August 2026, the National Environment Agency reports hotspots and dense smoke plumes over Kalimantan and southern Sumatra, with some over Riau. Dry conditions are expected to persist through the week, and with winds blowing from the south or south-east, Singapore can expect occasional periods of haze.

The readings that afternoon: the 24-hour PSI stayed within the moderate band, highest in the central region at 91. The 1-hour PM2.5 was normal across most of the island, but elevated in the central region at 65. Two weeks earlier, on 9 August, the central PSI had been 81 — so the direction of travel has been upward rather than settling.

The source is not in doubt. Indonesia's disaster agency recorded roughly 1,250 hotspots in the week to 21 August, more than 900 of them in Kalimantan alone, and has made tackling those fires a priority.

None of this is a surprise. The Government's Haze Task Force — 28 public agencies chaired by NEA — met twice during 2026 before the season even began. In June, the Singapore Institute of International Affairs issued a rare red alert in its annual Haze Outlook, with risk expected to peak across August and September.

Readings change hour by hour, so treat the numbers above as a snapshot rather than a forecast. NEA publishes live 24-hour PSI, 1-hour PM2.5 and air quality forecasts on its haze portal.

What the numbers next door tell us

If you want to know what haze does to a population, look at Malaysia, where the air has been worse for longer. Malaysia's Ministry of Health tracks haze-related illness through sentinel clinics, and the figures it reported on 23 August 2026 are stark.

Between epidemiological weeks 32 and 33 — roughly 9 to 22 August — asthma cases picked up by those clinics rose from 61 to 219. Upper respiratory tract infections rose from 1,637 to 3,674. Conjunctivitis, interestingly, fell slightly.

The timing is the part worth noting. Only a week earlier, on 15 August, the same ministry had reported no significant rise in haze-related illness. The jump came suddenly, once exposure had accumulated. That is the pattern haze tends to follow: nothing, nothing, nothing, then a wave of people who cannot breathe properly.

The scale is worth registering too. On 23 August, Malaysia's Air Pollutant Index Management System — which publishes hourly readings from 68 monitoring stations nationwide — had seven areas sitting in the unhealthy band and 61 more in the moderate band. Not one station recorded good air. This is a regional event, not a local one.

A note on the numbers, since both countries are in the news: Malaysia reports an API and Singapore reports a PSI. They are different indices and are not directly comparable, though the bands are read the same way — above 100 is unhealthy in both.

What haze actually does to your body

Haze is not simply smoke you can see. The pollutant that matters most is PM2.5 — particles small enough to travel past the nose and throat and reach deep into the lungs. Bigger particles get filtered out on the way in. These do not.

Once there, they irritate and inflame the airway lining. In a healthy person that usually produces the familiar nuisances: itchy eyes, a dry or sore throat, a blocked or runny nose, a cough that will not settle. Singapore's Ministry of Health puts it plainly — for healthy people, short-term exposure over a few days generally causes irritation of the eyes, nose and throat rather than anything more serious.

The problem is that airways which are already inflamed react differently. If you have asthma, the same particles can tip a well-controlled condition into an attack. If you have chronic lung disease, they can trigger a flare-up. And the strain is not only respiratory — fine particulate matter places extra load on the heart, which is why people with heart conditions are advised to be careful too.

Reading the PSI without overthinking it

The 24-hour PSI is the number the health advisories are built around. NEA publishes it, along with 1-hour PM2.5 readings and forecasts, on its haze portal.

• 0–50, Good — no precautions needed.
• 51–100, Moderate — fine for most people. If you have asthma or lung disease, this is the point to check your medication is on hand.
• 101–200, Unhealthy — NEA begins issuing daily advisories with next-day forecasts. Reduce outdoor exertion; if you have chronic heart or lung disease, avoid it.
• 201–300, Very unhealthy — minimise time outdoors.
• Above 300, Hazardous — stay indoors.

One caveat worth knowing: the 24-hour PSI is an average, so it lags behind what you are breathing right now. If the air looks and smells noticeably worse than the number suggests, the 1-hour PM2.5 reading is the more responsive figure.

PM2.5 has its own bands, and they carry their own advice. When it reaches the elevated range — as it did in the central region on 24 August — NEA's guidance is to consider easing off strenuous outdoor activity for the next hour. Vulnerable people, meaning the elderly, pregnant women, children and anyone with chronic lung or heart disease, should avoid strenuous outdoor activity at that point rather than merely reduce it.

Who needs to be more careful

Health advisories single out particular groups, and the distinction is not arbitrary — it reflects who actually turns up unwell.

• People with asthma — the group the Malaysian figures show being hit first and hardest.
• People with chronic lung disease, including COPD and bronchiectasis.
• People with heart disease — fine particles add cardiovascular strain, not just respiratory.
• Children — smaller airways, faster breathing, and more time spent running around outdoors.
• Older adults, particularly anyone with an existing heart or lung condition.
• Pregnant women — advised to minimise prolonged or strenuous outdoor exertion.

Everyone else is not immune, simply better buffered. Healthy people who exercise hard outdoors during haze can still end up with a cough that lingers well after the sky clears.

What you can do at home

• Cut outdoor exertion. Exercise makes you breathe harder and deeper, drawing more particles further in. Move the run indoors, or leave it for a clearer day.
• Drink water. NEA's standard advice, and it genuinely helps a dry, irritated throat.
• Keep windows shut when the air is bad, and run air-conditioning or a purifier if you have one.
• Use an N95 mask if you must be outdoors for long in unhealthy air. A surgical or cloth mask does not filter PM2.5.
• If you have asthma, check your inhalers now — before you need them. Confirm the reliever is not empty or expired, and keep taking your preventer even on days you feel well.

When to see a doctor

Most haze symptoms settle once the air clears. These do not fall into that category, and are worth a consultation rather than a wait.

• Wheezing, chest tightness or breathlessness — particularly if you have asthma and your reliever is not lasting as long as usual, or you are reaching for it more often.
• A cough that has not settled after the air has improved, or one bringing up discoloured phlegm.
• Fever alongside respiratory symptoms — that suggests infection rather than irritation, and infection needs treating.
• Eye symptoms that persist despite staying indoors, or eyes that become genuinely painful rather than merely gritty.
• Any chest pain, or breathlessness at rest.
• A child who is breathing fast, wheezing, feeding poorly or unusually drowsy.

Health advisories are consistent on this point: people who are unwell during haze — especially the elderly, children, and anyone with chronic heart or lung conditions — should seek medical attention rather than wait it out.

If you are struggling to breathe, cannot speak in full sentences, or your lips or fingertips look blue, that is an emergency. Call 995 or go to the nearest emergency department.

How Bethesda Medical can help

Our family physicians see the whole range of haze-related illness, from an irritated throat that needs reassurance to an asthma flare that needs treating properly. In a consultation we can:

• Assess your breathing and work out whether this is irritation, an asthma flare, or an infection that has taken hold.
• Treat an asthma or COPD flare-up, including nebulisation where it is needed.
• Review and adjust your inhalers — haze season is exactly when a preventer that has been quietly under-dosed shows itself.
• Treat respiratory infections, eye irritation and the sinus symptoms that often follow.
• Write an asthma action plan so you know what to do next time the PSI climbs, without having to guess.
• Refer you on if your symptoms point to something that needs specialist assessment.

You do not need to wait for things to get bad. If you have asthma or a chronic lung condition and the forecast is poor, a review before the air worsens is far easier than a flare-up in the middle of it.

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