It was a foggy morning in the national capital on Thursday with the minimum temperature recorded at 10.5 degrees Celsius and air quality deteriorating to "severe" level a day after Diwali.The air-quality across the National Capital Region has worsened, according to System of Air Quality and Weather Forecasting And Research (SAFAR) and the minimum temperature dipping three notches below normal."The sky will be clear with fog or mist in the early morning," an India Meteorological Department (IMD) official said.The maximum temperature was likely to hover around 28 degrees Celsius. The humidity at 8.30 a.m. was 86 per cent.On Wednesday, the city witnessed an improvement in the air quality as it reached "poor" level after reaching "emergency" levels on Tuesday early morning before coming down to "very poor" and "poor" levels.The maximum temperature on Wednesday settled at 27.8 degrees Celsius, a notch below the season's average, while the minimum temperature was recorded at 12.5 degrees Celsius, one notch below the season's average.