Delhi continued to simmer for a fourth consecutive day on Tuesday, as unfavourable meteorological conditions led to a peak “real feel” temperature or heat index (HI) of 53.5 degrees Celsius (°C) amid a yellow alert for rainfall and thunderstorms during the day falling flat, according to India Meteorological Department (IMD) data.Experts said that Delhi will see some relief from these heatwave-like conditions from Thursday, as the monsoon advances. (Raj K Raj/Hindustan Times)Experts said that while high humidity is expected to persist—it was between 48% and 65% on the day—Delhi will see some relief from these heatwave-like conditions from Thursday, as the monsoon advances.The city recorded a maximum temperature of 40.5°C, which was over 3°C higher than the normal, and a minimum temperature of 30.2°C, which was over 2°C higher than the normal. However, there was no heatwave on the day. “No heat wave was realised over Delhi today as we need a minimum of two stations over the subdivision Haryana-Chandigarh-Delhi. As per data received until now, heat wave criteria is satisfied only at one station over the Subdivision of Haryana-Chandigarh-Delhi,” the IMD said in a statement.ALSO READ | Dry heat from Pakistan, humid air from Arabian Sea: Why Delhi feels like 53°CThe city had recorded heatwaves on Sunday and Monday, as the maximum temperature exceeded 40°C and was at least 4.5°C above normal. To be sure, a heatwave is also declared when a temperature of 45°C or higher is recorded by at least two stations.While the city did not meet this criterion on Tuesday, the maximum temperature at the Delhi Ridge station was 41.5°C, which was 4.8°C above normal for this time of the year. The heat index peaked at 5.30pm, when the maximum was 37.6°C and the humidity was 60%.Due to the high humidity, the city also recorded high wet-bulb temperatures during the day, with readings of 29.7°C at 2.30pm, and 30.8°C at 5.30pm. The wet-bulb temperature is the lowest temperature that can be achieved through evaporative cooling against the actual temperature. A wet-bulb temperature of 32°C or higher makes it difficult for even fit and acclimatised people to work outdoors for long. At a value of 35°C — the highest reading on the scale — the human body can no longer regulate temperatures, leading to heatstrokes and collapse.ALSO READ | Monsoon expected by July 3-4 as heatwave-like conditions grip DelhiThe IMD has said that the city was likely to see relief from the heat from Thursday, with the maximum temperature expected to dip to 32-34°C by Friday, before a marginal rise. Additionally, the IMD stated that conditions were favourable for the monsoon to advance into “most parts of Haryana-Chandigarh-Delhi & Punjab, and some parts of Rajasthan during next 2-3 days.”