Air pollution worsened in the National Capital Region on Sunday after briefly improving on Saturday. Late on Sunday, pollution levels in and around Delhi were still at ‘severe’, the highest and worst category on the air quality index.

At 8 pm, levels of PM10 and PM2.5 were at 622 and 638 at Lodhi Road, and 584 and 568 in Noida, 544 and 512 at Terminal 3 of the Airport, according to the government’s System of Air Quality and Weather Forecasting And Research. It is only expected to marginally improve on Monday, though schools are likely to be open.

An Air Quality Index reading up to 50 is considered ‘good’, and up to 100 is considered ‘satisfactory’. A reading between 401-500 is ranked ‘severe’ on the index, which means the air is dangerously filled with pollutants.

Several trains to the Capital were delayed or cancelled earlier in the day.

The state government has cancelled its plans to ration the use of vehicles in the city’s roads after the National Green Tribunal asked it not to exempt anyone, including women and those using two-wheelers.

Smog might worsen from Wednesday

The pollution might get worse from November 15, after a light rain in the city. Though the rain may help marginally dissipate smog, in the long run it will lead to a buildup of moisture in the air – this could further trap pollutants in the air and cause temperatures to drop, according to the Hindustan Times. “We don’t know to what levels the pollution will spike to. But, we expect it would be milder than the present spell,” said Gurfan Beig, project director at Safar, was quoted as saying.

Since November 7, there has been severe smog due to pollution in Delhi and several other northern cities. The National Human Rights Commission had sent notices to the Centre and the governments of Delhi, Punjab and Haryana, calling the air quality a violation of people’s Right to Life, and asking what measures will be taken to improve the air.