New Delhi, Dec 12 (IANS): Air quality in Delhi and adjoining regions improved from "severe" to "very poor" on Wednesday as wind speed picked up due to western disturbance over north India and dispersed pollutants.

"The major reason for the improvement in Delhi's air quality is increased surface wind speed (4kmph from 2.5kmph) which will disperse pollutants slowly," System of Air Quality and Weather Forecasting and Research (SAFAR) said in its forecast.

However, the agency said, the drizzling in some parts of the national capital was proving to be "counterproductive" as it could not wash away particulate pollutants, instead increased the air holding capacity by introducing more moisture.

"Other than wind speed, rest all meteorological factors are likely to be unfavourable even tomorrow (Thursday)," it said.

Between Tuesday night and Wednesday, the weathermen informed, Delhi recorded 0.4 mm of rainfall.

The Air Quality Index (AQI) of Delhi at 4 p.m was 392 (very poor) against 413 (severe) on Tuesday, on a scale of 0 to 500.

In the national capital region (NCR), the air quality of Ghaziabad, however, remained in the "severe" category, with AQI at 409 - not much improvement from Tuesday's 433.

Faridabad, Greater Noida and Noida, however, improved to "very poor" with AQI at 357, 388 and 390, respectively.

"Air quality in Delhi will continue to remain between the upper side of 'very poor' and 'severe' category until December 14 due to western disturbance bringing moisture. There will be no rain from Thursday and the sky will remain mainly clear," said Mahesh Palawat, Director at private weather forecasting agency Skymet.

He further said that the minimum temperature from December 14 will start to fall and will hover around 6 degrees Celsius.

Delhi's minimum temperature at 8.30 a.m was recorded at 12.6 degrees Celsius with humidity levels reaching 98 per cent.

The maximum temperature on Wednesday was 21.6 degrees Celsius.

An official from the India Meteorological Department (IMD) said the sudden increase in the minimum temperature is also attributable to the western disturbances.

"Western disturbances over the northern part of India is active which is not posing any problem to air quality at present but withdrawal may increase moisture level in Delhi air after a few days," SAFAR said.