Delhi September AQI Hits 5-Year Low at 102
Delhi records its lowest September average AQI in five years, showing a consistent improvement in air quality trends for 2026.
In a significant development for the capital's environment, Delhi has recorded its lowest monthly average Air Quality Index (AQI) for the month of September in the last five years. The Ministry of Environment, Forest and Climate Change announced on Wednesday that the city's average AQI for September 2026 stood at 102, signaling a continued positive trend in air quality improvement.
A Five-Year Comparative Analysis
The data released by the ministry highlights a steady decline in pollution levels during this period. When compared to previous years, the September 2026 figure of 102 is notably lower than the averages recorded in the preceding five-year cycle:
- September 2026: 102
- September 2025: 105
- September 2024: 105
- September 2023: 108
- September 2022: 104
This downward trend suggests that the measures taken to manage urban pollution are yielding measurable results as the city moves through the year.
More 'Moderate' Days and Fewer 'Severe' Days
The improvement is not just reflected in the average numbers but also in the frequency of air quality categories. Between January and September 2026, Delhi witnessed a record number of days with a daily average AQI below 200, which falls under the 'Moderate' category. The city recorded 194 such days this year, surpassing the counts from 2025 (187 days), 2024 (188 days), 2023 (193 days), and 2022 (146 days).
Conversely, the number of days categorized as 'Poor to Severe+' has hit a five-year low. During the January to September period of 2026, Delhi recorded only 79 such days. This is a marked improvement from the 86 days recorded in both 2025 and 2024, 80 days in 2023, and the high of 127 days seen in 2022.
PM2.5 Concentrations on the Decline
The ministry also noted that the average PM2.5 concentration in Delhi from January to September 28, 2026, is among the lowest levels seen since 2022. The average PM2.5 concentration for 2026 was recorded at 69 micrograms per cubic metre (µg/m³), matching the 2025 levels. This is a significant drop from the concentrations of 81 µg/m³ in 2024, 73 µg/m³ in 2023, and 80 µg/m³ in 2022.
Ongoing Efforts Ahead of Winter
The Commission for Air Quality Management (CAQM) is reportedly working in tandem with various stakeholders to implement effective measures for the prevention and control of air pollution across the Delhi-NCR region. The ministry emphasized that these efforts will be intensified in the coming days.
This proactive approach comes at a critical time, as the city prepares for the winter season. Historically, Delhi-NCR faces a deterioration in air quality during the colder months due to a combination of shifting meteorological conditions and various emission sources.