The air quality in Delhi on Friday remained "poor" and it is expected to slip into "very poor" category on Saturday as the effect of rainfall would be over, the weather office said.
The Air Quality Index (AQI) at 4 p.m was recorded at 249 (poor) against Thursday's 194 (moderate), on a scale of 0 to 500.
In the National Capital Region (NCR), Gurugram, Noida and Ghaziabad had AQI at 103, 230 and 286, respectively.
Faridabad and Greater Noida fared "poor" with AQI at 237 and 285, respectively.
"Today's air quality is poor. However, it is likely to slip down to "very poor" from tomorrow (Saturday), as rainfall impact is over and all other weather conditions are adverse. However, winds are still moderate, which may not allow it to accumulate faster," the System of Air Quality and Weather Forecasting and Research (SAFAR) said in its forecast.
It has predicted that air quality for next two days is likely to be "very poor".
As per the data of the Central Pollution Control Board (CPCB), the average concentration of PM2.5 and PM10 in Delhi at 4 p.m. was 112 and 194 microgrammes per cubic metres. Across NCR, it was 110 and 190 units, respectively.
Due to meteorological conditions, Monday and Tuesday in Delhi-NCR were the worst breathing days of the month with air quality levels reaching "severe" category, between 401-500.
The air quality had improved to "poor" on Thursday after overnight rains.