New Delhi, Jan 18 : Amid the ongoing cold wave, the minimum temperature in the national capital plunged to 2.6 degrees Celsius on Wednesday, according to India Meteorological Department (IMD). While the Safdarjung Observatory recorded 2.6 degrees Celsius, the Palam area registered a low of 6 degrees and Lodhi road was at 2.2 degrees. According to the weather man, rainfall or thunderstorm is likely between January 22 and 25 with peak activity on January 23 and 24 over the plains of northwest India, including Punjab, Haryana, Uttar Pradesh, and north Rajasthan. "However, light to moderate hailstorm is likely at isolated places over Jammu, Himachal Pradesh, Uttarakhand, Punjab, Haryana, Chandigarh, Delhi, west Uttar Pradesh and north Rajasthan on January 23 and 24," it said. The IMD has also predicted strong surface winds (speeds reaching 30-40 Kmph) with gusty winds (speeds reaching 50 Kmph) as very likely to prevail over Punjab, Haryana, Delhi and west Uttar Pradesh occasionally on January 23 and 24. In the national capital, the air quality has entered into a "very poor" category with overall AQI at 316. Notably, 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". At Pusa, the AQI was recorded at 318 falling under "very poor" category. The Air Quality Index reached 245 at Lodhi Road, while in Ayanagar, it was at 273. According to the forecast from the System of Air Quality and Weather Forecasting And Research (SAFAR), the air quality of the city will deteriorate further on Thursday. /IANS