Live · Singapore · updated hourly

Air quality in Singapore today, in cigarettes

Today's fine-particle pollution (PM2.5) over Singapore converted into the number of cigarettes you are effectively smoking just by breathing.

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About air pollution in Singapore

Singapore is one of 115 cities with a dedicated live page on ToolNest. The figure above is recalculated every time you open the page from the latest hourly output of the Copernicus Atmosphere Monitoring Service (CAMS), a global model that blends satellite data, ground stations and weather forecasts. Because it is a model at roughly 10-40 km resolution, it describes the air over the Singapore metropolitan area rather than a single street; busy roads and industrial zones are typically worse, parks and waterfronts better.

Day-to-day changes in Singapore's PM2.5 are driven mostly by weather. Wind and rain clear particles; calm, cold nights trap them close to the ground. Seasonal sources such as heating, agricultural burning, wildfire smoke and dust can push a city from "Good" to "Unhealthy" within hours, which is why the seven-day bars and tomorrow's forecast are shown alongside today's number.

What to do at each level

Today's categoryCigarettes/daySensible response
Good< 0.5Enjoy outdoor activities.
Moderate0.5–1.6Fine for most people; very sensitive individuals may notice symptoms during long, hard exercise.
Unhealthy for sensitive groups1.6–2.5Children, older adults and people with lung or heart disease should cut back on prolonged outdoor exertion.
Unhealthy2.5–5.7Everyone should reduce heavy outdoor exercise; consider an N95/FFP2 mask and an indoor air purifier.
Very unhealthy / Hazardous5.7+Stay indoors with windows closed and filtered air. Avoid all outdoor exertion.

How the calculation works

The comparison comes from Berkeley Earth, whose researchers matched the mortality risk of long-term PM2.5 exposure with that of smoking: 22 µg/m³ of PM2.5 breathed for 24 hours ≈ 1 cigarette. We divide the day's average PM2.5 by 22. The "right now" pace uses the latest hour instead of the daily average, so it swings more. AQI colours follow the US EPA PM2.5 scale (2024 breakpoints). Read the full methodology on the Air Quality in Cigarettes hub.

Frequently asked questions

Is the air in Singapore safe to breathe today?

The live panel at the top of this page shows today's PM2.5 level for Singapore as a cigarette equivalent and an AQI category. "Good" and "Moderate" are fine for most people; from "Unhealthy for sensitive groups" upwards, children, older adults and anyone with asthma or heart disease should limit time outdoors.

How is the cigarette number for Singapore calculated?

We take the 24-hour average concentration of fine particles (PM2.5) over Singapore from the CAMS atmospheric model and divide it by 22 µg/m³, the amount Berkeley Earth found to be equivalent to one cigarette per day.

Why does this differ from the official Singapore air quality index?

National indices use different breakpoints and often include other pollutants such as ozone or nitrogen dioxide. This page focuses on PM2.5 because it is the pollutant most comparable to cigarette smoke, and uses the US EPA scale for the colour categories.

When is air pollution in Singapore usually worst?

In most cities PM2.5 peaks during rush hours, on still winter days when heating emissions are trapped near the ground, and during regional events such as wildfire smoke, dust storms or crop burning. Check the 7-day bars to see how today compares with the rest of the week.

Data: Open-Meteo Air Quality API (CAMS / Copernicus, CC BY 4.0). Method: Berkeley Earth (2015). For general information only; not medical advice.