PSI
24-hour rolling index—Unavailable
No hourly readings available
—
NEA observation
I wonder what the air
is like today…
Swipe or drag up to look outsideor tap / click the bamboo
Checking the latest air readings…
Central region selected · use ⊙ for your location
Loading hourly readings…
Tap a name to show or hide its line.
Shared numeric scale · PM₂.₅ in µg/m³, PSI and AQI as indices.
SGT · slide through the day
Central
The air, hour by hour.
Past 24 hourly readings · SGT
PM₂.₅
1-hour · µg/m³—Unavailable
No hourly readings available
—
NEA observation
US AQI
Estimated—Unavailable
No hourly readings available
—
Open-Meteo · CAMS model
Choose this tab to load history.
Hourly readings
| Time · SGT | PSI | PM₂.₅ µg/m³ | US AQI estimated |
|---|
PSI is a rolling 24-hour index reported each hour. PM₂.₅ is the 1-hour observation. US AQI is a model estimate. Move the slider to inspect an hour. Lines share a numeric scale: PSI and AQI are indices; PM₂.₅ is in µg/m³. They measure different things. Line colours identify the measure; number colours show its category. Gaps indicate unavailable readings.
Air Quality Measurements
Different measures. Different timeframes. Here’s how to read them.
PSI
Pollutant Standards Index
Singapore’s index summarises six pollutants; the highest pollutant sub-index determines the reading. This app shows NEA’s 24-hour PSI, updated hourly.
An index, with no physical unit.
- 0–50
- Good
- 51–100
- Moderate
- 101–200
- Unhealthy
- 201–300
- Very unhealthy
- 301+
- Hazardous
Source: NEA · PSI explained (PDF) ↗
PM₂.₅
Fine particulate matter
Airborne particles about 2.5 micrometres or smaller. This app shows the amount measured over one hour, in micrograms per cubic metre (µg/m³).
These bands choose the illustrated haze.
- 0–55
- Normal
- 56–150
- Elevated
- 151–250
- High
- 251+
- Very high
Sources: NEA · 1-hour bands ↗ · US EPA · particles ↗
AQI
Air Quality Index
The US AQI expresses air quality and related health concern. Here it is an Open-Meteo / CAMS model estimate, rather than an NEA sensor reading.
A different scale and averaging method from PSI.
- 0–50
- Good
- 51–100
- Moderate
- 101–150
- Unhealthy for sensitive groups
- 151–200
- Unhealthy
- 201–300
- Very unhealthy
- 301+
- Hazardous
Sources: AirNow / US EPA · AQI ↗ · Open-Meteo · model ↗
A NOTE FROM THE MAKER
Hello, I’m KG Wee.
Haze With You began with a small question: what if checking the air felt like opening a window?
What do you think?
Ideas, bugs, or a small detail you enjoyed? I’d love to hear your comments and feedback.
Thank you for taking a look through the window.