The grove is holding its breath.
Long exposure can cause breathing illness. Stay indoors where you can, and wear an N95 mask outside.
Every light is a city's grove.
Spin the Earth and zoom in. Each Indian city is a grove with a light pillar as tall as its PM2.5: clean cities glow green, polluted ones go grey under their own haze. Play the smoke week to watch crop fires flare in Punjab and Haryana, then the groves downwind grey one after another.
Your city's air, on one card.
The hour you're looking at, the next three days and how sure the forecast is. It follows the time slider and the city you pick. Drag it to see the back.
On the finished site you can save the card as an image to share.
The next 72 hours in Delhi
Hourly PM2.5 for the last three days and the forecast ahead. The shaded band is where the real value should fall eight times out of ten.
How good is the forecast?
Average error in µg/m³, lower is better. Each forecast was made only with data available at that moment, then compared with three simpler ways to predict the air.
| Method | 1–6 h | 7–24 h | 25–72 h |
|---|
In October and November, "same hour yesterday" beats it 2–3 days ahead (53 vs 60). Its 10 worst days are all smoke spikes it underestimated, like the day after Diwali: 281 observed, 139 forecast.
The 80% range held the real value 78% of the time, so the band means what it says.
CAMS is the official global forecast, shown here without local bias correction. A corrected version closes much of the gap; both appear in the full report.