Central Singapore read PSI 146 at 8 am on 12 October 2026, after a peak of 192 on 9 October (NEA, 2026). The bigger fact is the floor: on 5 to 11 October, 163 of 168 hours sat in NEA's Elevated PM2.5 band or above. No clean hour was left to wait for, so check the 1-hour PM2.5.
A rider leaving central Singapore at 7 am in September met 43 µg/m³ of PM2.5. Last week the same ride met 88 (NEA hourly feed, 2026). Same road, same breathing, about twice the dose. Nobody rides at the 192 peak. Riders ride at 7 am and 6 pm, and those hours stopped offering relief.
The week the clean window closed
NEA publishes hourly PM2.5 through data.gov.sg. I pulled central Singapore for every hour from 4 September to 11 October and grouped it by week. "Elevated" means NEA's 1-hour band of 56 to 150 µg/m³.
Until October the haze came in surges, with clean hours in between. In the week of 18 to 24 September the cleanest hour read 6. Last week it never dropped below 49, and the week averaged 101 µg/m³, about 6.7 times the WHO 24-hour guideline of 15 (WHO, 2021).
The peak wasn't what changed. Central PSI hit 186 at 2 pm on 9 October (The Star, 2026) and 192 by 8 pm. What grew in 2026 is how long it lasts.
Use the 1-hour PM2.5 for the ride you are about to take. NEA itself says to use it for immediate decisions and the PSI forecast for planning.
Why the same ride delivered twice the dose
What you breathe in is roughly air quality times breathing rate times time. On your usual commute, only the air changed.
Average PM2.5 in central Singapore, µg/m³. 4 Sep to 4 Oct vs 5 to 11 Oct.
It also breaks advice from earlier on this site. Our guide to the best time of day to ride said early mornings were cleaner. In September that held. Last week it did not.
Why the station number is only a floor for a rider
A rider sits in queues, right next to the exhaust. In Makassar, motorcycle riders breathed 4 times the PM2.5 and 13 times the PM10 of car passengers on the same roads (Patel et al., 2016). Nobody has measured the multiplier for Singapore yet.
In Thailand, motorcycle taxi drivers' own PM2.5 didn't track the nearest station at all (Samana et al., 2025). And in Hanoi, black carbon on motorcycles ran at 29.4 µg/m³ against 10.1 in buses (Quang et al., 2021). No public index reports black carbon.
In Singapore's own hospital data, each 30-unit rise in PSI came with 2.3% more respiratory emergency visits (Chan et al., 2020) and 4% more heart attacks (Ho et al., 2019). Those are island-wide averages. Riders sit at the sharp end.
Ride with filtered air
Filters haze PM2.5 on every ride
Easi Breezi clips onto any helmet and feeds you H11 HEPA-filtered air. Bike-powered, no batteries, no charging.
Why timing and masks run out
When every hour is elevated, picking a better time to ride stops working. That leaves whatever sits between the air and your mouth.
In a Barcelona traffic test of nine commercial masks, PM2.5 protection ranged from 14% to 96% on the same air, with a median of 48% (Pacitto et al., 2019). In Makassar, only surgical masks lowered rider exposure consistently (Patel et al., 2016). Fit and seal decide most of it.
| Protection | What decides it | What the research found |
|---|---|---|
| Open vents and visor | Ram air, which fails in a queue | Nothing is filtered |
| Cloth or disposable mask | Model and seal | 14% to 96% on the same air (Pacitto et al., 2019) |
| Surgical mask | Seal and breathing rate | Only type that lowered exposure consistently (Patel et al., 2016) |
| Timing the ride | A clean hour existing | Cleanest hour 49 µg/m³, 5 to 11 Oct (NEA hourly feed, 2026) |
See what happens inside a regular helmet in smoke:
When will it end?
NEA's 11 October update still forecasts unhealthy air, with smoke from southern Sumatra and West Kalimantan carried in on south-easterly winds (NEA, 2026). Showers over Singapore are not rain over the fires. Our when will the haze be gone post tracks the signals that matter.
It won't be the last season either. Singapore's unhealthy-haze years were 2013, 2015, 2019, 2023 and 2026, roughly one every three years (see our haze trend analysis), and NOAA has a strong El Niño likely into early 2027 (NOAA CPC, 2026). Plan around the floor, not the peak.
Filtering the air at your face when there is no clean hour
Easi Breezi runs off your bike, with no battery. It draws air through an H11 HEPA filter, rated to stop 95% of PM2.5, and sends it into your helmet, so the air at your face doesn't depend on a lull in the haze. Specs are on the product page.
Don't want to keep checking?
What to do this week
- Check the 1-hour PM2.5 before you leave. Use NEA's live reading, not this morning's PSI.
- Stop assuming mornings are cleaner. The 7 am average was 88 µg/m³ last week.
- Cut idling time where you can. Your air at tailpipe height is worse than any rooftop station shows.
- Re-seat any mask on every ride. Fit separated 14% from 96% in the Barcelona test.
- Filter the air at your face. See how an active HEPA system works when no clean hour is coming.
How bad is the air where you ride right now?
Check your city's air nowFrequently asked questions
What is the PSI in Singapore now?
At 8 am on 12 October 2026, central Singapore read PSI 146 and the west read 147 (NEA, 2026). The 1-hour PM2.5 was 78 µg/m³ in the central region. Check the live NEA reading before you leave, because this one will be out of date.
Is the 24-hour PSI or the 1-hour PM2.5 better for deciding when to ride?
The 1-hour PM2.5. NEA says to use it for immediate decisions and the 24-hour PSI forecast for planning (NEA, 2026). Our Singapore central region post explains why the two diverge.
Does the PSI tell me what I breathe on a motorcycle?
No. Treat any station number as a floor for a rider. Thai motorcycle taxi drivers' personal PM2.5 did not track the nearest station (Samana et al., 2025).
The research behind this (6 peer-reviewed studies)
Each card says what was measured, what was found, and what it cannot tell you. None of these studies measured a rider in Singapore's haze: three are about Singapore's haze, three are about riders elsewhere.
Haze exposure in Singapore schoolchildren
- What they measured
- A portable monitor on 46 Singapore schoolchildren for 24 hours, with hourly activity logs, in haze and non-haze periods. Haze particles were then tested on human bronchial cells.
- What they found
- Exposure was higher in haze and higher again while commuting, and haze particles drove more inflammatory signals in the cells.
- What it can't tell you
- Children, not riders. The cell test is a lab model, not a clinical outcome.
PSI and emergency care, nationwide
- What they measured
- 5,791,945 emergency visits and 1,552,187 admissions at Singapore public hospitals from 2010 to 2015, matched to daily PSI.
- What they found
- No link to total visits. But each 30-unit PSI rise came with 2.3% more respiratory emergency visits and 2.7% more respiratory admissions.
- What it can't tell you
- Daily PSI is an island average, not personal dose, and the effect per unit is modest.
PSI and heart attacks
- What they measured
- All 53,948 heart attacks in Singapore's national registry from 2010 to 2015, compared with PSI on the days around each event.
- What they found
- Each 30-unit PSI rise came with 4% more heart attacks. Days in the "unhealthy" band had 9% more.
- What it can't tell you
- An association from registry data. It does not prove haze caused any single event.
Motorcycle vs car exposure
- What they measured
- Handheld particle counters on motorcycle, minibus and car trips in Makassar, Indonesia, plus tests of surgical masks, bandanas and motorcycle masks.
- What they found
- Against cars, average motorcycle exposure was 4 times higher for PM2.5 and 13 times higher for PM10. Only surgical masks lowered it consistently.
- What it can't tell you
- A non-haze baseline, so the gap in a haze week is probably larger, but that was not measured.
Motorcycle taxi drivers vs the nearest station
- What they measured
- Personal PM and PAH sampling on motorcycle taxi drivers in six central Thai provinces, January to March 2023 (the Thai winter).
- What they found
- Pathum Thani drivers averaged 410.9 µg/m³ of personal PM2.5, and personal readings were independent of the fixed stations.
- What it can't tell you
- No individual lung-function link. Thai winter months (January to March), not Singapore's haze.
Black carbon on a motorcycle
- What they measured
- Black carbon sensors running at the same time on motorcycles and in bus and car cabins in Hanoi.
- What they found
- Average black carbon was 29.4 µg/m³ on motorcycles against 10.1 in buses.
- What it can't tell you
- A pilot study in one city. Black carbon sits in no public index, so no station reports it.
Sources
- National Environment Agency, Singapore (2026). Real-time PM2.5 and PSI hourly feed, data.gov.sg. Pulled 12 October 2026.
- George, S. et al. (2020). Personal level exposure and hazard potential of particulate matter during haze and non-haze periods in Singapore. Chemosphere.
- Chan, S. L. et al. (2020). Impact of air pollution and trans-boundary haze on nation-wide emergency department visits and hospital admissions in Singapore. Annals of the Academy of Medicine, Singapore.
- Ho, A. F. W. et al. (2019). Time-stratified case crossover study of the association of outdoor ambient air pollution with the risk of acute myocardial infarction in the context of seasonal exposure to the Southeast Asian haze problem. Journal of the American Heart Association.
- Patel, D., Shibata, T., Wilson, J., Maidin, A. (2016). Challenges in evaluating PM concentration levels, commuting exposure, and mask efficacy in reducing PM exposure in growing, urban communities in a developing country. Science of the Total Environment.
- Samana, K., Ito, K., Suthienkul, O., Ketsakorn, A. (2025). Analysis of PM-bound polycyclic aromatic hydrocarbons exposure among motorcycle taxi drivers in six central provinces in Thailand in winter. PLOS ONE.
- Quang, T. N. et al. (2021). Motorcyclists have much higher exposure to black carbon compared to other commuters in traffic of Hanoi, Vietnam. Atmospheric Environment.
- Pacitto, A. et al. (2019). Effectiveness of commercial face masks to reduce personal PM exposure. Science of the Total Environment.
- World Health Organization (2021). WHO global air quality guidelines.
- National Environment Agency, Singapore (2026). Haze Situation Update, 11 October 2026.
- NOAA Climate Prediction Center (2026). ENSO diagnostic discussion, 8 October 2026.
- The Star (2026). Haze in Singapore: PSI hits 186, 2026 high in central region (9 Oct).
Written by Ash, mechanical engineer and founder of Easi Breezi, building an active HEPA filtration system for motorcycle helmets (patent pending). Based between Hong Kong and Bali, riding daily in the traffic this blog writes about.