Delhi’s 52.9 degree temperature row: Kiren Rijiju reveals correct figure
Earth sciences minister Kiren Rijiju said on Saturday that the record temperature of 52.9 degree Celsius, registered this week in Delhi’s Mungeshpur area, was wrong by 3 degree Celsius.
The temperature reading recorded on May 29 in the city’s northwestern fringes was the highest ever recorded anywhere in India.
“On 29th May 2024, Mungeshpur’s AWS (Automatic Weather Station) reported a temperature of 52.9°C; our @Indiametdept team quickly investigated and found a 3°C sensor error. Corrective measures are now in place,” Rijiju wrote on X.
The minister cited a draft report submitted by a committee chaired by IMD experts.
“A committee chaired by Mrs Ranju Madan, Sc-G, comprising experts from IMD, was tasked to review this anomaly. The committee’s investigation included an evaluation of the AWS sensor at Mungeshpur and comparisons with other AWSs in Delhi,” the draft report shared by the minister said.
“Their findings revealed a positive bias in the temperature readings, with AWS at Mungeshpur reporting temperatures approximately 3 degrees higher than standard instruments during the peak temperature period,” he added.
The committee also found no significant temperature discrepancies reported by other Delhi AWS stations.
The experts also recommended that the Surface Instrument Division in Pune examine and calibrate the AWS temperature sensors periodically for all the AWS. It also recommended a Factory Acceptance Test in different temperatures and routine maintenance of the AWS installed nationwide.
“If possible, a third-party audit should be done to authenticate the data quality of AWS. Stringent automatic quality control should be applied to the observed data from AWS before uploading to the (IMD) website for the general public and various users,” he said.
Since 1875, the IMD has been recording weather parameters at conventional observatories. At present, the weather agency operates over 550 surface observatories for weather forecasting, but this manual network is insufficient for continuous monitoring of weather systems like cyclones and monsoons.
To improve this, IMD has expanded its network with Automatic Weather Stations (AWS) to reduce human intervention. Since the summer of 2022, IMD has installed AWS at 15 new locations across Delhi and NCR, enhancing weather monitoring alongside existing manual stations.
AWS measures ambient air temperature, relative humidity, precipitation, wind speed, and wind direction hourly. These stations automatically observe and transmit weather data, reported in Indian Standard Time (IST) on a 24-hour clock.