PM2.5
PM 2.5
Just Tell Me
PM2.5 means fine airborne particles measuring 2.5 micrometres or less; Singapore reports their concentration to help people understand air quality, especially during haze.
Also called: PM 2.5, PM₂.₅, Fine particulate matter, 1-hour PM2.5
Explain Like I’m Five
The “2.5” describes the size of the particles, not today’s pollution score. The reading tells you how much of this fine material is in the air. These particles are the main pollutant during Singapore’s transboundary haze episodes.
Where You’ll Run Into It
Beside PSI on NEA’s haze website and the myENV app. The one-hour reading describes recent conditions and is paired with bands and a personal activity guide.
A monsoon forecast describes seasonal weather, rather than the concentration of particles in the air.
Example
“Which figure are you looking at—the one-hour PM2.5 or the 24-hour PSI?”
Two neighbours comparing air-quality reports may be looking at different measurements and time periods.
The Part People Get Wrong
A PM2.5 concentration is not a PSI score. Its units, µg/m³, mean micrograms of particles per cubic metre of air. It should be read using the matching PM2.5 bands, not compared directly with the numbers on the PSI scale.
Sources
Related
- housingMonsoon in SingaporeUpdated
A monsoon is a seasonal wind pattern that helps shape Singapore’s weather, including when prolonged rain or brief thunderstorms are more likely.
- moneyNEA (National Environment Agency)Updated
NEA is Singapore’s National Environment Agency, responsible for environmental protection, public cleanliness and hygiene, waste management, weather services and hawker-centre development.
- housingPSI (Pollutant Standards Index)Updated
PSI is Singapore’s air-quality index, turning measurements of six pollutants into a number that describes pollution levels.