Chandigarh, Nov. 15 -- Having remained largely satisfactory post Diwali, the city's air quality deteriorated to the moderate category on Saturday amid falling temperatures and changing wind patterns. Experts, however, said the air quality index (AQI) could improve as a Western Disturbance is active over the region, and may bring rain on Sunday. Some parts of the city also experienced drizzle on Saturday evening. According to the daily bulletin issued by the Central Pollution Control Board (CPCB), the city's AQI - 24-hour average of readings from the three monitoring stations in Sectors 22, 25 and 53 - stood at 111 on Saturday. An AQI of 0-50 is classified as good, 51-100 as satisfactory, 101-200 as moderate, 201-300 as poor, 301-400 as very poor and 401-500 as severe. Moderate air quality may cause breathing discomfort to people with lung and heart ailments. On Diwali night, the city's air quality had plunged to the very poor category but recovered to moderate levels the following day before improving further to satisfactory. Explaining the latest spike in AQI, Chandigarh Pollution Control Committee (CPCC) director (environment)-cum-member secretary Saurabh Kumar said the change was likely due to falling temperatures and shifting wind patterns. "The temperature has recently started falling. The wind pattern has also changed, due to which pollutants are not dispersing," he said, adding that weather conditions had so far remained favourable, helping keep the AQI in the satisfactory category. Kumar further said even 15 minutes of light rain could help settle dust particles and improve air quality. India Meteorological Department (IMD) Chandigarh director Surender Paul said the western disturbance would continue to influence the region on Sunday. The maximum temperature dipped marginally from 30degC on Friday to 29.9degC on Saturday, three degrees above normal. The minimum temperature fell from 15.2degC to 14.1degC, two degrees above normal. Over the next three days, the maximum temperature is expected to remain between 27degC and 28degC, while the minimum is likely to hover between 11degC and 13degC....