Delhi records hottest, most polluted April in three years amid rain deficit

New Delhi: A prolonged spell of dry westerly winds and a sharp decline in rainfall have led to Delhi experiencing its hottest April in three years, alongside a significant deterioration in air quality.

Data from the India Meteorological Department (IMD) shows the Capital’s average maximum temperature for April stood at 39°C, exceeding the long-period average by 2.5 degrees. The last time Delhi recorded higher April temperatures was in 2022, when the monthly average touched 40.4°C. Night-time temperatures also remained unusually warm, with the average minimum temperature at 21.8°C — the highest for April since 2022.

An IMD official attributed the above-normal heat to a near-absence of western disturbances and the resulting lack of rain across much of northwest India. “Delhi-NCR received very limited rainfall. Maximum temperatures stayed above normal on most days, especially during the second week,” the official noted.

Between April 7 and 9, the city experienced three consecutive heatwave days, meeting IMD’s threshold of over 40°C daytime temperatures and at least 4.5°C above normal. No heatwave days were observed in April 2023 or 2024, though 11 such days occurred in April 2022.

Rainfall remained scarce. Delhi received only 0.7 mm of rain this April, well below the monthly average of 16.3 mm. The lack of precipitation, combined with clear skies, contributed to rising temperatures and worsening air quality. “Dry and dusty conditions have prevailed throughout the month,” said Mahesh Palawat, vice president at private weather agency Skymet. “With no meaningful rain to cleanse the air, pollutants have remained suspended.”

The city’s average Air Quality Index (AQI) for April was recorded at 211, classified as ‘poor’ — the worst for the month since 2022, when the AQI reached 255. This month saw 20 days with ‘poor’ air quality, compared to seven in April 2024 and 13 in 2023. Palawat warned that while an approaching western disturbance could bring brief relief in early May, it may not last. “Cloudy conditions and some rain are expected in the first few days of May, but temperatures are projected to rise again in the second week,” he said.

On Tuesday, the maximum temperature dipped slightly to 37.5°C, while the minimum rose to 24.5°C. IMD forecasts similar conditions on Wednesday with surface winds between 20 and 30 km/h. A yellow alert has been issued for Thursday through Saturday, with gusts up to 50 km/h and chances of scattered showers.

The air quality remained in the ‘poor’ category for the ninth day in a row, with the AQI at 209 at 4 p.m. Tuesday. Authorities predict a slight improvement to ‘moderate’ levels by Wednesday.