The colors follow the standard air-quality bands for daily-average PM2.5 (µg/m³):
| 0–12 | Good. Clean air; no restrictions. |
| 12–35 | Moderate. Acceptable; unusually sensitive people should watch for symptoms. |
| 35–55 | Unhealthy for sensitive groups. Children, the elderly, and people with asthma or heart/lung disease should limit prolonged outdoor exertion. |
| 55–150 | Unhealthy. Everyone may feel effects; sensitive groups should stay indoors. Masks (N95/KN95) recommended outdoors. |
| 150–250 | Very unhealthy. Health warnings; avoid outdoor activity, keep windows closed, run purifiers if available. |
| 250+ | Hazardous. Emergency conditions — serious risk for the entire population. This is the level Palangka Raya reaches during severe karhutla episodes. |
The number in each chip is PM2.5 — the daily average concentration of fine smoke particles (smaller than 2.5 micrometers) in the air, in micrograms per cubic meter (µg/m³). These are the particles in wildfire haze that penetrate deep into the lungs; they are the reason smoke is dangerous, not the smell or the visibility.
For reference, the WHO guideline for a healthy daily average is just 15 µg/m³ — a “hazardous” day of 300+ is twenty times that.
The forecast comes from Copernicus CAMS, the European atmosphere model, which ingests the satellite fire detections and weather to predict where the smoke goes. Four chips = today plus the next three days.
Forecast refreshes every 3 hours. Model: CAMS global atmospheric composition via Open-Meteo.