When is the air worst? PM2.5 by hour, month, weekday and year, from CPCB monitoring data, 2009–2025.  Rising & falling stations  ·  ← Back to archive
Loading…

Hour of day × month

Average PM2.5 by month

Average across all years, with ±1 SD error bars for the typical spread within each month. Bars use CPCB colours. Hover for values.

Long-term monthly trend

Monthly average PM2.5 over time. The shaded band is ±1 SD of readings within each month, so a wider band means more variable readings. The bold line is a LASSO fit through the trend; the dashed line is the overall median. Background tints are CPCB bands.

Year on year

Monthly average PM2.5 for each year. Read down a column to see whether a given month is getting better or worse.

Day of the week

Average PM2.5 by weekday, with 95% confidence intervals from across-day variability. Overlapping intervals mean the differences are not meaningful.