New Delhi, Oct. 25 -- Gurugram on Friday recorded an air quality index of 219 ("very poor"), marginally down from the reading of 208 recorded a day before. Meanwhile in Delhi, after four consecutive days of "very poor" air, increased wind speed improved the air quality in the Capital to the "poor" level, leading Delhi to clock a 24-hour average air quality index (AQI) reading of 275, according to the Central Pollution Control Board's (CPCB's) daily bulletin. The AQI a day prior was 305 ("very poor".) Throughout the day, the real-time air quality continued to improve; it was 290 at 9am, 286 at 11am and 272 at 6pm. An AQI of 51 to 100 is classified as "satisfactory", 101 to 200 is classified as "moderate", 201 to 300 is classified as "poor", 301 to 400 is classified as "very poor" and over 400 is "severe", as per the CPCB. According to CPCB data for Friday, 38 air quality stations were active in Delhi and of them, the one at Anand Vihar , remained in the "severe" range throughout the day, with an AQI of 407 ("severe") at 6pm, in contrast to "poor" or "very poor" readings across other zones. However, the overall improvement is likely to remain short-lived, according to forecasts. The Air Quality Early Warning System (AQEWS) for Delhi suggests that the AQI might return to "very poor" level over the next few days."The air quality is very likely to be in the poor category on Saturday. The air quality is very likely to be in the very poor category from Sunday to Monday. The outlook for the subsequent six days is that the air quality is likely to be in the very poor to poor category," the AQEWS bulletin on Friday evening read. Sunil Dahiya, founder and lead analyst at the think-tank Envirocatalysts, said, "The wind speed had picked up on Friday morning, but is expected to drop in the evening hours. So, the pollution level might oscillate between poor and very poor for the next few days." Meanwhile, the India Meteorological Department (IMD) has said that a western disturbance is expected to start influencing the region from Monday. "A fresh western disturbance likely to impact Western Himalayan Region and adjoining northern plains of India from October 27 to morning of October 29. Under its influence, possibility of one or two spells of very light rain or drizzle is likely over Delhi from evening of October 27 to morning of October 28," an IMD official said. Dahiya said that given the western disturbance brings a spell or two of very light to light rain, air quality might see further improvement. "However, if there is no rain, the western disturbance might bring more dusty winds, which can lead to a spike in pollution level," he said. Delhi's minimum temperature on Friday was 17 degrees Celsius (degC), 0.2degC below normal....