The humidity at 8.30 a.m. was 100 per cent, causing the sudden spike in the pollution levels.
The India Meteorological Department (IMD) told IANS that the sky was expected to remain clear with mist during the day.
The maximum temperature was likely to hover around 27 degrees Celsius.
At 9 a.m., the major pollutant concentration PM2.5 or particles with diameter less than 2.5 micrometers were 273 microgrammes per cubic meters around Delhi, while it was 272 across NCR — about 10 times the international safe limits.
According to System of Air Quality and Weather Forecasting And Research (SAFAR), the Air Quality Index of Delhi at 9 a.m. was 379 on a scale of 0 to 500.
The IMD has predicted the air-quality and visibility to improve from January 23 as it was most likely to rain.
Thursday’s maximum temperature was 27.7 degrees Celsius, highest in January so far, while the minimum temperature was recorded at seven degrees Celsius.