Delhi’s temperature didn’t cross 50 degrees. It almost touched it, says IMD | India News

Following alarming reports of temperatures reaching 52 degrees Celsius in Delhi’s Mungeshpur and 56 degrees Celsius in Nagpur, the Ministry of Earth Sciences, in collaboration with the India Meteorological Department (IMD), has clarified that the sensor readings were incorrect.

Did the temperature in Delhi really touch 52.9 degrees?

On May 29, the IMD reported that its Mungeshpur weather station recorded a temperature of 52.9 degrees, the highest ever recorded in India. The next day, the Nagpur weather station reported the mercury rising to 56 degrees, causing nationwide concern.

The committee tasked with reviewing the anomaly compared these readings with other automatic weather stations (AWS) in Delhi, revealing a positive bias in the temperature readings at Mungeshpur. The AWS at Mungeshpur reported temperatures approximately 3 degrees Celsius higher than standard instruments during peak periods. This means that the peak temperature in parts of Delhi on May 29 was around 49.9 degrees Celsius.

Meteorological officials noted that these high temperatures were recorded because areas like Mungeshpur, Narela, and Najafgarh are particularly susceptible to the early arrival of hot winds from Rajasthan, exacerbating the severe weather.

The table of maximum temperatures across various AWS and observatories in Delhi showed a significant spike at Mungeshpur (52.9 degrees Celsius) compared to the next highest at Najafgarh (49.7 degrees Celsius). The AWS at Mungeshpur consistently reported higher temperatures than standard instruments, with differences ranging from 1.9 degrees Celsius to 3.1 degrees Celsius.

The report also noted that no significant discrepancies were found in temperatures reported by other AWS stations in Delhi.

Was Nagpur boiling at 56 degrees?

Additionally, on May 31, the IMD clarified that the 56 degrees Celsius recorded in Nagpur was due to a malfunction of temperature sensors.

“On 30th May, PDKV Ramdaspeth (Nagpur City IMD automatic weather station) reported a maximum temperature of 54.4 degrees Celsius, and another station in Nagpur reported 52.2 degrees Celsius. These values are incorrect due to a failure of the electronic sensor (as confirmed by IMD, Pune),” the IMD posted on X.

It added that at the nearby functioning AWS at the Central Institute for Cotton Research (CICR), the maximum temperature reading was 44 degrees Celsius.

IMD’s AWS instruments under scrutiny

The faulty readings have brought the AWS instruments into question. Experts pointed out that if maintenance is not proper and the AWS is placed in an inappropriate location, such as a rooftop or over a concrete structure, it can be affected by the nearby topography and overheat.

They said it was natural for an AWS to overheat, but the scientist who took the reading should have been careful before making it public.

Now, the committee investigating the Mungeshpur and Nagpur incidents has made recommendations regarding the installation and maintenance of AWS. It recommended that corrections be applied in cases of standard bias for accurate temperature representation.

Factory acceptance tests must be conducted at different temperatures during AWS installation. The committee also recommended that site acceptance tests should compare AWS temperatures with standard instruments continuously for at least 24 hours at hourly intervals.

Routine maintenance of AWS installations across the country and third-party audits should be systematically planned to authenticate data quality, the IMD asserted.

The ministry has recommended that stringent automatic quality control be applied to AWS data before public dissemination to avoid public panic.

First Published: Jun 01 2024 | 4:01 PM IST