Delhi: Incessant rains and hailstorm across the northern plains have led to plummeting of mercury levels, bringing the minimum temperature down to 12.8 degrees Celsius in the national capital. There was, however, no respite in the pollution levels in the city with overall air quality index in the 'poor' category.

While partly cloudy sky has been predicted for Friday, the city is likely to witness moderate to-dense fog in the next 48 hours, India Meteorological Department (IMD) said. From 8.30 am to 5.30 pm, Safdarjung recorded 4mm, Palam 0.8mm, Ridge 2.8mm, Aya Nagar 1.7mm and Najafgarh 1mm rain. At 6.4mm, Lodhi Road saw maximum rain.

According to IMD, a western disturbance as a cyclonic circulation way lying over central Pakistan and the neighbourhood is bringing scattered rain to north and parts of central India.

At 9.5 degrees Celsius, the minimum temperature in Delhi settled two notches above normal while the maximum was 16.4, three notches below normal, a Met official said. On Friday, the maximum and minimum temperatures will be around 17 and 8 degrees Celsius, respectively. Very light rain may be witnessed in isolated parts of the city.

However, despite rain, the pollution levels in the national capital increased slightly as the overall air quality index touched 281 in the 'poor' category against Wednesday's 218 in the same category.

According to SAFAR, a central forecast body, an improvement in the air quality to the moderate-to-lower end of the 'poor' category is expected by Friday. AQI is likely to be at the higher end of the category on Saturday, according to the Skymet weather.

An air quality between 0-50 is considered "good", 51-100 "satisfactory", 101-200 "moderate", 201-300 "poor", 301-400 "very poor" and 401-500 "severe".

Capital's popular marketplace Chandani Chowk witnessed a 'very poor' AQI of 302 while Mathura roadsaw 285. While adjoining Uttar Pradesh's Noida recorded a similar 'poor' air quality with the AQI standing at 276.