Delhi swelters as temperature nears 40°C

IMD officials said that the temperature in Delhi is expected to decline over the next few days, reducing the likelihood of heatwave-like conditions

New Delhi

Kids in Noida cover their heads to protect themselves from the heat. (Sunil Ghosh/HT Photo)

The Capital grudgingly welcomed the summer sun on Wednesday, as some parts near the ridge and Pitampura recorded a maximum temperature over 40 degrees Celsius (°C). The maximum temperature at the Safdarjung observatory—considered the standard for the Capital—was 38.9°C, the hottest March day in around three years, since a maximum of 39.5°C degrees was recorded on March 31, 2022, according to the India Meteorological Department (IMD).

At the Ridge station, the maximum temperature was 40.1°C and at Pitampura station, it was 40.6°C.

The temperature at the Safdarjung station was 7.4°C above normal and 1.8°C higher than last year’s. To be sure, March 2022 was the warmest March in 122, according to IMD data, with an average of 33.1°C. The average in March 2025 so far has been 32.1°C.

Weather officials, however, said the weather conditions could not be classified a “heatwave” as, according to IMD, a “heatwave day” when the maximum is 4.5°C above normal and the maximum is over 40°C. It is also considered a”heatwave day” when the maximum temperature crosses 45°C. A “severe heatwave” is declared when the maximum is over 6.5°C higher than the normal, when the maximum is above 40°C.

“We need these conditions to be fulfilled at two stations on two consecutive days to declare a heatwave in any region,” an IMD official said.

IMD officials said that the temperature in Delhi is expected to decline over the next few days, reducing the likelihood of heatwave-like conditions. “On Thursday, we are expecting slight fall of 1-2°C and the day after that, an abrupt fall of 3-4°C is expected. We are also expecting strong surface winds during the daytime after Friday,” the official said.

The IMD forecast wind speed to reach 20-30kmph, in the west-northwest direction, by Friday, from a speed of around 15kmph at present.The department forecast the maximum temperature to remain in the 34-36°C and the minimum in the 17-19°C.

“Delhi’s record-breaking heatwaves are a direct consequence of climate change, driven by global fossil fuel dependence. While renewable energy efforts are underway, they remain insufficient to counter the crisis. Short-term fixes won’t help—only decisive action can avert future disasters. With 1.5°C likely breached, this summer could be even harsher. We need heat action plans, not just on paper, but urgently implemented on the ground,” said Sunil Dahiya, founder and lead analyst, Envirocatalysts.

On Wednesday, the IMD had issued hot day warnings for most of north India, specifically for adjoining Uttar Pradesh. At least 24 cities across the country clocked temperatures higher than 40°C, with a spike in minimum and maximum temperatures by up to 2°C between Tuesday and Wednesday.

In adjoining Gautam Budh Nagar district, the maximum and minimum temperatures were 38°C and 18.2°C.

Air quality ‘poor’

Delhi’s 24-hour average air quality index (AQI) was 231 (“poor”) at 4pm, according to the Central Pollution Control Board’s (CPCB’s) daily bulletin. This was a marginal improvement from the AQI of 234 recorded a day earlier.

However, the pollution level across NCR cities were varied. Faridabad in Haryana recorded an AQI of 78 (“satisfactory”), based on readings from four weather stations. AQI was “moderate” in Noida (154) and Greater Noida (186), while it was 263 (“poor”) in Gurugram and 312 (“very poor”) in Ghaziabad.

CPCB classifies AQI between 0 and 50 as “good,” between 51 and 100 as “satisfactory,” between 101 and 200 as “moderate,” between 201 and 300 as “poor,” between 301 and 400 as “very poor,” and over 400 as “severe.”

This was also the third consecutive “poor” air day in Delhi since Sunday, after a slew of “moderate” air days. The Commission for Air Quality Management (CAQM) for Delhi-NCR also imposed Stage 1 of the Graded Response Action Plan (Grap) over the past two days.

Forecasts by the Air Quality Early Warning System (AQEWS) for Delhi predicted the air quality is likely to improve marginally due to increased wind speed and will stay “moderate” over the next few days. “The air quality is likely to be in the moderate category on Thursday. The outlook for subsequent three days is that the air quality is likely to be in the ‘moderate’ category,” the AQEWS bulletin.