New Delhi: Delhi-NCR's air quality on Tuesday morning reached ‘severe’ category with more farm fire plume blowing towards the region, and a decrease in the wind speed and temperature hampering dispersion of pollutants.

At 8 am on Tuesday, the AQI in Noida’s Sector 62 (768) reached the ‘severe-plus emergency’ category.

The monitoring stations at ITI Jahangirpuri (741), Vasundhara in Ghaziabad (714), DITE Okhla (624), Bawana (792), Rohini (692), Narela (698), Mundka (735), and Anand Vihar (666) also recorded the air quality in the "severe-plus" category.

An AQI between 201 and 300 is considered 'poor', 301-400 'very poor' and 401-500 'severe'. An AQI above 500 falls in the 'severe plus' category.

The city’s Air Quality Index (AQI) bordered on "severe" levels on Monday and the Ministry of Earth Sciences' air quality monitor, SAFAR, had warned of the worsening air quality from Tuesday.

On Monday, the city's overall air quality index read 360 at 4 pm, up from 321 on Sunday.

Kuldeep Srivastava, head of the India Meteorological Department's regional weather forecasting centre, said the spike in pollution levels can be attributed to a significant decline in the wind speed -- from 20 kilometers per hour over the last two days to 10 kilometers per hour on Monday.

He said incidents of stubble burning in Haryana and Punjab have increased and northwesterly winds have been bringing more farm fire plume to the Delhi-NCR region.

A dip in the temperature has also led to accumulation of pollutants near the ground, he said.

SAFAR said the effective stubble fire count on Sunday was 1,846.

"Stubble plume intrusion is expected to increase and a decrease in surface wind speed over the Delhi region is predicted for the next two days," it added.