Diwali 2026 Air Quality Forecast: What to Expect & How to Protect Yourself
Updated March 2026 · 10 min read · City-by-city predictions
2026 Diwali Date (Estimated)
Diwali 2026 falls on approximately October 20–21, 2026. Based on 10 years of historical data, Delhi's PM2.5 will likely spike to 600–1,000+ μg/m³ on the night of Diwali — 120–200× the WHO safe limit. Plan protection measures in advance.
10 Years of Delhi Diwali Pollution Data
| Year | Delhi Peak PM2.5 (μg/m³) | Diwali Night Avg PM2.5 | Context |
|---|---|---|---|
| 2019 | 999 | 620 | Extremely severe — pre-pandemic, record firecracker use |
| 2020 | 590 | 380 | Moderate — pandemic reduced outdoor activity and firecracker sales |
| 2021 | 850 | 510 | Severe — post-pandemic rebound + unfavorable winds |
| 2022 | 640 | 420 | High — High Court allowed green crackers; poor ventilation |
| 2023 | 720 | 480 | High — ban on firecrackers largely unenforced |
| 2024 | 680 | 450 | High — persistent pattern despite partial enforcement |
Note: AQI (0–500 US EPA scale) corresponds to different PM2.5 concentrations. Peak PM2.5 of 999 μg/m³ = AQI "Hazardous" (500+). Many monitoring stations use 999 as the upper limit of their sensors.
2026 City-by-City Forecast
| City | Pre-Diwali AQI | Peak Forecast | Post-Diwali (+1–3 days) | Risk |
|---|---|---|---|---|
| Delhi NCR | 150–200 | 600–1,000+ | 300–450 (days 1–3) | Extreme |
| Patna | 130–180 | 450–700 | 250–380 | Very High |
| Kanpur / Lucknow | 120–170 | 400–650 | 220–350 | Very High |
| Kolkata | 80–120 | 250–450 | 150–250 | High |
| Mumbai | 60–90 | 120–280 | 80–150 | Moderate–High |
| Bangalore | 50–70 | 100–220 | 60–120 | Moderate |
| Chennai | 45–65 | 90–200 | 55–110 | Moderate |
| Hyderabad | 55–75 | 110–230 | 65–130 | Moderate |
Hour-by-Hour Guide for Diwali Night
Pre-event baseline
Prepare: stock N95 masks, check air purifier filter
Slight rise (AQI +20–50)
Early firecrackers begin; close windows if you plan to stay indoors
Moderate rise (AQI +50–150)
Puja and lamps lit; firecracker activity increasing rapidly
Heavy smoke (AQI +200–500)
Peak firecracker hours; PM2.5 rising sharply; turn on HEPA purifiers, wear N95 outdoors
Peak pollution (AQI 500–1,000+)
Most dangerous period; avoid outdoor exposure; keep windows and doors sealed; run purifiers at maximum
Still very high (AQI 300–700)
Firecrackers tapering but temperature inversion traps smoke; continue indoor precautions
Highly polluted (AQI 200–450)
Avoid outdoor morning walk; residual PM2.5 from overnight accumulation; still wear N95 if going outside
Elevated (AQI 150–350 in north India)
Gradual improvement depending on wind and rain; continue HEPA purifier use; minimize strenuous outdoor activity
Diwali Protection: Complete Checklist
Before Diwali (1 week before)
- ✓Buy N95/KN95 masks — one per family member (buy extra, they sell out before Diwali)
- ✓Check and replace HEPA air purifier filters if older than 6 months
- ✓Stock up on any respiratory medications (inhalers, antihistamines if sensitive)
- ✓Identify which rooms to seal for the night (bedroom is priority)
- ✓Download AQI monitoring app (Airvisual or SAMEER) and set alerts
On Diwali Day
- ✓Run HEPA purifier from 4 PM onwards to pre-clean indoor air before pollution peaks
- ✓Close all windows and doors from sunset onward
- ✓If joining outdoor celebrations, wear N95 mask during firecracker bursting periods
- ✓Return indoors before 8 PM to avoid peak pollution window
- ✓Give vulnerable family members (children, elderly, asthma patients) priority for cleanest room
Note on Firecracker Bans
The Supreme Court and several state governments have issued Diwali firecracker restrictions ranging from complete bans to "green crackers only" policies since 2017. Enforcement has been inconsistent — historical data shows no significant reduction in Diwali night pollution in ban years vs. non-ban years in Delhi. While policy advocacy for stricter enforcement is valuable long-term, protective measures remain necessary regardless of official restrictions.