The national capital's air quality is likely to improve further within the poor category on Wednesday due to a favourable wind speed, authorities said.

The city's air quality index (AQI) read 236 at 9 am. The 24-hour average AQI stood at 255 at 4 pm on Tuesday.

Neighbouring Faridabad (190), Ghaziabad (220), Greater Noida (136), Gurgaon (184) and Noida (180) also recorded improvement in their air quality.

An AQI between zero and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe.

The Ministry of Earth Sciences' air quality forecast agency SAFAR said moderate wind speed over the next three days will further improve ventilation.

Mahesh Palawat, Vice President (Meteorology and Climate Change), Skymet Weather, said moderate wind speed will help improve the air quality further.

He said that cold northwesterly wind will commence from Friday after a Western Disturbance affecting the hilly region recedes, causing the minimum temperature to drop by two to three degrees Celsius.

Delhi recorded a minimum temperature of 10.1 degrees Celsius, a notch more than normal.

The maximum temperature is likely to settle around 24 degrees Celsius. The minimum temperature is likely to drop by two to three degrees Celsius over the next three to four days, the Met office said.