October 2025: A challenging month for Delhi's air and weather
October proved to be a tough month for Delhi residents, as the city's air quality not only worsened but also set several new records. According to data from the Central Pollution Control Board (CPCB), October 2025 was the second most polluted October in the past five years. The average Air Quality Index (AQI) for the month stood at 224, placing it in the 'poor' category. While this figure is slightly better than last October's 234, it remains higher than the AQI levels recorded in 2023 (218), 2022 (210), and 2021 (173). Despite this, the CPCB noted that significant rainfall helped temper both temperatures and pollution levels. October 2025 turned out to be the coldest October in the last three years, with rainfall preventing pollution from worsening further. Without this rainfall, experts say, Delhi's air quality could have deteriorated even more sharply. The average maximum temperature for the month was 31.5°C, lower than the normal average of 33°C. The last time Delhi saw a lower October maximum was in 2022, at 31.4°C. Several days of rain in the first week kept the air relatively clean, but conditions shifted after October 12, when the dry spell and rising emissions pushed the AQI from poor to very poor, a trend that continued until Diwali. Local pollution is the main culprit, not stubble burning According to Anumita Roychowdhury, Executive Director at the Centre for Science and Environment (CSE), the deterioration in air quality during October was largely due to local pollution sources. She noted that stubble burning contributed only 1–2% to the pollution levels, underscoring that the main causes lie within the city — vehicle emissions, construction dust, and industrial pollution. "It's essential to control these local sources if we want cleaner air," she told News18 Hindi.
