The minimum temperature in the national capital on Tuesday settled at 18.8 degrees Celsius, a notch above the normal.

Delhi on Monday had recorded its hottest day of the season at 39.1 degrees Celsius, seven notches above the season's average, with the temperature expected to rise further in the next couple of days.

The relative humidity at 8:30 AM on Tuesday stood at 48 per cent, according to data shared by the India Meteorological Department.

On Monday, the Safdarjung Observatory had recorded a high of 39.1 degrees Celsius and a low of 22.2 degrees Celsius.

The maximum temperature on Tuesday is likely to hover around 40 degrees Celsius, and heat wave has been forecast.

The minimum and maximum temperature readings on Wednesday are likely to settle at 22 degrees Celsius and 40 degrees Celsius respectively, according to IMD data.

The air quality index (AQI) of Delhi was recorded in the poor category (reading 272) in the morning, data from CPCB showed around 9:15 AM.

An AQI between zero and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe.