Guide

Go by the 1-hour PM2.5. Above 55, cut down strenuous outdoor activity, and if you are in a vulnerable group, avoid it.

• Band II (56 to 150): healthy people reduce strenuous outdoor activity. The elderly, pregnant women, children and people with heart or lung disease avoid it.
• Band III (151 to 250): healthy people avoid strenuous outdoor activity. Vulnerable groups avoid all outdoor activity.
• Band IV (251 and above): healthy people minimise all outdoor activity. Vulnerable groups avoid it.
• For the next day, follow the 24-hour PSI forecast and advisory. This app's answer for now follows the 1-hour PM2.5.

Source: NEA PSI and PM2.5 guide · MOH haze advice

The 1-hour PM2.5 for the next few hours, and the 24-hour PSI forecast to plan the next day.

• PM2.5 is the main pollutant of concern in smoke haze.
• The 24-hour PSI averages the past day, so the 1-hour PM2.5 shows changes sooner.

Source: NEA PSI and PM2.5 guide · NEA: managing haze

Both start from the same NEA reading. AQICN puts it on a US scale, and that scale gives bigger numbers.

• AQICN: NEA's PM2.5 for the last hour, changed to the US scale.
• NEA's PSI: the past 24 hours, from six pollutants. In haze, PM2.5 is the main one.
• Both scales go from 0 to 500. For the same PM2.5, the US scale climbs faster:
• PM2.5 of 12 µg/m³: PSI 50, AQICN 50.
• PM2.5 of 35 µg/m³: PSI 76, AQICN 99.
• PM2.5 of 55 µg/m³: PSI 100, AQICN 149.
• PM2.5 of 100 µg/m³: PSI 147, AQICN 173.
• AQICN's words for its numbers:
• 0 to 50: Good.
• 51 to 100: Moderate.
• 101 to 150: Unhealthy for sensitive groups.
• 151 to 200: Unhealthy.
• 201 to 300: Very unhealthy.
• 301 and above: Hazardous.
• When haze comes in fast, the last-hour reading goes up first. So AQICN can rise hours before the PSI.
• On the Now card, the line under "Right now" shows the AQICN number for that reading.
• The advice in this app uses NEA's PSI and PM2.5 bands.

Source: NEA PSI and PM2.5 guide · AQICN Singapore page · AQICN scale

A 24-hour PSI of 101 and above is deemed unhealthy.

• Good: 0 to 50.
• Moderate: 51 to 100.
• Unhealthy: 101 to 200.
• Very unhealthy: 201 to 300.
• Hazardous: above 300.

Source: NEA PSI and PM2.5 guide · NEA: managing haze

Forest fires in the region, started by open burning to clear land.

• Dry seasons, wind direction and low rainfall make it worse.
• Winds carry the smoke over Singapore, particularly in the Southwest monsoon.

Source: NEA: managing haze · NEA air pollution FAQ

Not for short trips like commuting, or indoors.

• Healthy people who must be outdoors for several hours may wear one when the PSI forecast is Hazardous (above 300) or the 1-hour PM2.5 is in band IV.
• The elderly, pregnant women and people with heart or lung disease may wear one when the PSI forecast is above 200 or the PM2.5 is in band III.
• Surgical masks do not filter fine particles, and an N95 only works with a good fit.

Source: NEA air pollution FAQ · MOH haze advice

The elderly, pregnant women and people with severe heart or lung problems who have difficulty breathing at rest or on exertion.

• Anyone who feels uncomfortable should take a break from the mask.

Source: MOH haze advice · NEA air pollution FAQ

During bad haze the Government gives free N95 masks to eligible Singaporeans at Community Clubs and mask vending machines. HazeMaskGoWhere shows who is eligible, where to collect and which places have stock.

• Bring the eligible person's NRIC.

Source: HazeMaskGoWhere · Haze Task Force release

Close doors and windows when the air outside is getting worse, and open them again when it improves.

• Fans and aircon are fine.
• If the aircon draws in unfiltered outside air, such as a window unit, close its outdoor air intake.

Source: NEA air pollution FAQ

One with a HEPA filter, big enough for the room.

• Its smoke CADR should be at least 3 times the room volume in cubic metres.
• For example, a 4 by 3 m bedroom with a 2.6 m ceiling is about 31 m³, so look for a smoke CADR of at least 94 m³ per hour.

Source: NEA air pollution FAQ

At haze shelters: air-conditioned rooms in Community Clubs and selected Residents' Committee and Residents' Network centres.

• They open to the public when the PSI enters Very unhealthy (above 200).
• Shelters in Community Clubs stay open until 10pm if the PSI turns Hazardous.

Source: Haze Task Force release

Minimise prolonged or strenuous outdoor exertion when the 24-hour PSI forecast is above 100.

• Avoid outdoor activity when it is above 300.
• There is no certified mask standard, such as N95, for children.
• MOH says the AIR+ Smart Mask can be used only where necessary by children without heart or lung conditions, if it keeps a good seal.

Source: NEA air pollution FAQ · MOH haze advice

MOE considers closing schools when the next day is forecast Hazardous (24-hour PSI above 300).

• A closure is announced when the health advisory is issued.
• Below that, schools cut outdoor activity as the PSI rises and keep pupils in rooms with air purifiers.

Source: MOE haze measures

At Very unhealthy, preschools stop all outdoor and strenuous indoor activity.

• Children stay indoors with doors and windows closed, and a room with an air purifier is set aside.
• Children with heart or lung conditions skip all indoor physical activity.

Source: ECDA, in the Haze Task Force release

MOM's guidelines: less outdoor work as the PSI rises, and protection for staff who still work outdoors.

• For healthy staff: reduce prolonged or strenuous outdoor work at PSI 101 to 200, avoid it at 201 to 300, and minimise outdoor work above 300. Limits are stricter for vulnerable staff.
• Fit-test masks for staff still working outdoors, and keep at least a 1-week supply of N95s.
• Use measures such as job rotation, indoor rest breaks and enough water.

Source: MOM employer guidelines · Haze Task Force release

If you feel unwell or have trouble breathing, especially if you are elderly, a child or have a heart or lung condition.

• In healthy people, a few days of haze may irritate the eyes, nose and throat, which usually clears on its own.
• Haze can worsen heart and lung disease, and symptoms may show up 1 to 3 days after exposure.

Source: MOH haze advice · NEA air pollution FAQ

NEA advises pregnant women to reduce exposure to haze for the health of the unborn baby.

• PSI 101 to 200: minimise prolonged or strenuous outdoor exertion.
• PSI 201 to 300: minimise outdoor activity.
• Above 300: avoid outdoor activity.
• In the 2nd and 3rd trimesters, stop using an N95 if it feels uncomfortable.

Source: NEA air pollution FAQ · NEA PSI and PM2.5 guide

Yes, while MOH's Haze Subsidy Scheme is active. It has been active since 12 Oct 2026.

• All Singapore Citizens qualify at polyclinics.
• At participating Public Health Preparedness Clinics (look for the PHPC decal), it covers children 18 and below, seniors 65 and above, and some card holders such as CHAS Blue and Orange.
• For conditions like asthma and bronchitis, eligible citizens pay no more than $10, Pioneer and Merdeka Generation no more than $5, and Public Assistance card holders nothing.

Source: MOH Haze Subsidy Scheme · MOH haze advice