India, in Infographics: Environment
78% Of Delhi’s Worst Air Days Fall In Just Three Months, November To January
Delhi’s Daily Air Quality Index Since 2016, One Row Per Season From March To February, With The Paddy Burning Window Marked. Hover Or Tap A Day.
Each Thin Bar Is One Day, Coloured By The CPCB Category Of Delhi’s 4 PM AQI, With Each Season Running From 1 March To The End Of February. The Dashed Lines Mark 15 September And 30 November, The Window In Which CAQM Monitors Paddy Burning. Hover Or Tap A Day For Its Value. On A Phone, Each Season Is A Column Running From March At The Top To February At The Bottom.
November To January
78%
657 Of 839 Very Poor Or Severe Days
Inside The Paddy Window
316
15 September To 30 November, 38%
After It Closes
468
December To February, 56%
Rest Of The Year
55
1 March To 14 September, 7%
The Bottom Line
Over Ten Seasons, 78% Of Delhi’s Very Poor Or Severe Air Days Fell In November To January. 316 Fell Inside The 15 September To 30 November Paddy Burning Window And 468 In December To February, After It Closed.
What The Data Shows
Three Months Carry The Year
Over Ten Seasons, March 2016 To February 2026, Delhi Had 839 Very Poor Or Severe Days. 657 Of Them, 78%, Fell Between 1 November And 31 January.
Most Come After The Paddy Window
316 Of Those Days Fell Inside The 15 September To 30 November Window In Which CAQM Monitors Paddy Burning; 468 Came In December To February, After It Closed.
No Steady Decline
Very Poor Or Severe Days Ranged From 69 In 2019-20 To 104 In 2016-17; 2025-26 Had 80.
Read With Care
Timing Is Not Cause
The Chart Shows When Bad Days Fall, Not What Causes Them. This Page Does Not Apportion Delhi’s Pollution Among Its Sources.
Calendar Dates
Crop Dates Are Windows From Law, The State And PAU’s Advice, Not Field Observations. Harvest Ends Vary By Variety And Year.
Capped At 500
The Index Tops Out At 500, So The Worst Days Of Each Winter Look The Same On This Scale.
Sources & Method
Data
Delhi AQI: CPCB Daily AQI Bulletins, 4 PM City Value, 1 January 2016 To 8 November 2026, The Same Series As Our Daily Delhi AQI Graphic Plus 5 To 8 November. Seasons Run 1 March To The End Of February; Very Poor Is 301 To 400, Severe 401 To 500.
Crop Calendar
Punjab Preservation Of Subsoil Water Act 2009 (No Paddy Nursery Before 10 May; Transplanting From A Notified Date, 1 To 9 June By Zone In 2026, As Reported). PAU Package Of Practices: Nursery 20 May To 20 June, Transplanting To 10 July, Wheat Sowing Fourth Week Of October To Fourth Week Of November. Paddy Procurement Opens 1 October. CAQM Monitors Paddy Burning 15 September To 30 November And Wheat Burning 1 April To 31 May.
Data: CPCB AQI Bulletins · PAU · CAQM (PIB).
