Delhi experienced a chilly winter morning on Tuesday with the minimum temperature dropping to 5.1 degrees Celsius, three notches below the season's normal as the air quality continued to be very poor. Experts advised against any outdoor activity early morning and after sunset, and to wear N-95 or P-100 respirators when stepping out. "Mist covered Delhi skies in the morning but the rest of the day will be clear without any signs of clouds. Haze or smoke will appear later in the day when the temperature drops," an India Meteorological Department (IMD) official told IANS. The maximum temperature was expected to reach 23 degrees Celsius while the minimum will be around 5 degrees Celsius, the Met said. The humidity at 8.30 a.m. was 94 per cent - a condition considered unfavourable for pollutants to disperse. As per the Central Pollution Control Board (CPCB) data, the average concentration of PM2.5 and PM10 in Delhi at 10 a.m. were 205 and 357 microgrammes per cubic metres, respectively. Across the National Capital Region (NCR), it was between 191 and 341 units, respectively.