Delhi gets teaser rain as monsoon approaches

The brief spell of rain also broke a five-day streak of ‘satisfactory’ air in the city, as Delhi’s air quality index (AQI) slipped back to the ‘moderate’ category

Overcast skies, sticky humidity, and a light drizzle across parts of Delhi on Monday offered a curtain-raiser to the approaching monsoon, which is likely to reach the Capital within the next 48 hours, according to the India Meteorological Department (IMD).

Dark clouds above the Jama Masjid in New Delhi on Monday. (Sanjeev Verma/HT Photo)

The brief spell of rain also broke a five-day streak of ‘satisfactory’ air in the city, as Delhi’s air quality index (AQI) slipped back to the ‘moderate’ category. This five-day clean air run was the joint longest in June since 2020, Central Pollution Control Board (CPCB) data showed.

The IMD has issued a yellow alert for light to moderate showers on Tuesday and Wednesday, with light rain likely to continue through the weekend. “Conditions are favourable for rain in the city. Light to moderate showers are expected on both Tuesday and Wednesday,” said an IMD official.

In its evening bulletin, the IMD said monsoon currents were likely to advance over more parts of Rajasthan, Punjab, Haryana, Chandigarh and Delhi, as well as West UP, Himachal Pradesh and Jammu over the next two days.

The normal onset date of the south-west monsoon over Delhi is June 27. It arrived a day late last year on June 28, bringing 228mm in a single day. In 2022, it reached on June 25, with 48.3mm.

On Monday, Safdarjung—the city’s base station—recorded 4.1mm of rainfall between 8.30am and 5.30pm, while Lodhi Road logged 4.3mm. No other stations reported rain.

Delhi has now logged 93.1mm of rain so far this June, already exceeding the month’s long-period average (LPA) of 74.1mm. In contrast, June 2023 saw 243.4mm—over three times the average.

Despite the showers, humidity dominated the day. The maximum temperature was 36.2°C—two degrees below normal—but the relative humidity of 68% pushed the Heat Index (‘real feel’) to a sultry 48.5°C. Humidity fluctuated between 60% and 89% through the day.

The wet-bulb temperature stood at 29.72°C. Readings above 32°C hinder the body’s ability to cool itself, with 35°C considered the theoretical limit for human survivability.

The minimum temperature was 28.2°C, normal for this time of year. On Tuesday, maximum and minimum temperatures are expected to hover around 34–36°C and 25–27°C, respectively.

Meanwhile, Delhi’s average AQI was 112 (moderate) at 4pm Monday, compared to 92 (satisfactory) the day before. CPCB data classifies AQI between 101–200 as ‘moderate’, and 51–100 as ‘satisfactory’.

The Centre’s Air Quality Early Warning System has forecast a return to ‘satisfactory’ levels on Tuesday, aided by the rain.