Full Breakdown
Delhi’s Coldest October Day in Decades Triggers Record Rainfall and Air-Quality Improvement
By Drooid · · How we work
In this breakdown
01
Record-Breaking Weather on October 30
On Friday, October 30, the India Meteorological Department (IMD) recorded a maximum temperature of 20.7 °C at the Safdarjung observatory—the lowest October high since records began in 1951. Nearby stations reported similar lows: Palam 20.5 °C, Lodhi Road 20.6 °C, the Ridge 20.8 °C and Ayanagar 20.4 °C, each 10 °C–11 °C below the seasonal norm.
The same day brought 61.4 mm of rain in a 24-hour period ending 8:30 a.m., the wettest October day in four years. Cumulative rainfall at Safdarjung reached 123.3 mm, making October 2026 the fourth-wettest October on record since 1954 and the sixth-highest 24-hour October total since 1951.
Air quality also improved sharply. The Central Pollution Control Board (CPCB) reported an AQI of 60, the cleanest October reading since October 10 2022 (AQI 44). The Centre for Research on Energy and Clean Air (CREA) calculated a monthly average AQI of 167, the lowest October value since 2015.
02
Meteorological Drivers
The IMD attributed the sudden cooling and precipitation to the interaction of a western disturbance with the remnants of Cyclone Arnab, generating widespread cloud cover, isolated thunderstorms and heavy rain across Delhi-NCR and adjoining states.
Visual evidence
Images from the story
03
Quantitative Highlights
Swipe across the table to see all columns.
| Parameter | Value | Source |
|---|---|---|
| Max temperature (Safdarjung) | 20.7 °C | IMD |
| Min temperature (Safdarjung) | 17.2 °C (1.1 °C above normal) | IMD |
| Rainfall (Safdarjung, 24 h) | 61.4 mm | IMD |
| Cumulative October rainfall (Safdarjung) | 123.3 mm | IMD |
| AQI (city-wide, Oct 30) | 60 (cleanest since Oct 10 2022) | CPCB |
| AQI (near India Gate, Oct 30) | 93 (satisfactory) | CPCB |
| Monthly average AQI (Oct 2026) | 167 (lowest since 2015) | CREA |
| Transport sector contribution to pollution (Oct 30) | 17.8 % | DSS |
| Industrial sector contribution | 3.5 % | DSS |
| Residential sector contribution | 4.6 % | DSS |
| Farm-fire incidents (Oct 30) | 44 (40 Punjab, 4 Rajasthan) | IARI |
04
Official Weather and Air-Quality Alerts
- The IMD issued red and orange alerts for heavy rain, thunderstorms and strong winds across Delhi-NCR on October 29–30.
- The Air Quality Early Warning System projected moderate air quality through October 31 and a shift to poor on early November.
- The CPCB classifies AQI 0-50 as “good”, 51-100 as “satisfactory”, 101-200 as “moderate”, 201-300 as “poor”.
05
Conflicting Reports & Gaps
- The city-wide AQI of 60 (CPCB) contrasts with a 93 reading near India Gate (CPCB) and a 90 figure reported by the Indian Express for the same day, leaving the precise city-wide level ambiguous.
- While the IMD cites 61.4 mm of rain at Safdarjung, the Tribune India report notes a higher monthly total of 123.3 mm but does not break down daily contributions beyond the 24-hour figure.
06
What’s Next
- The Air Quality Early Warning System expects moderate conditions on October 31, deteriorating to poor in early November.
- Forecasts for the weekend predict maximum temperatures of 23 °C–25 °C on Saturday, rising to 28 °C–30 °C by Sunday, and 29 °C–31 °C on Monday.
- The IMD warns of additional rain and thunderstorms in central, eastern and southern India through early November, including widespread rainfall over coastal Karnataka, Kerala, Telangana and coastal Andhra Pradesh.
These developments mark a rare early-winter shift for Delhi, linking a historic cold snap and heavy rain to a notable, though temporary, improvement in the capital’s air environment.