IMD says Delhi's record 52.9 degrees Celsius temperature was wrong by 3 C

The weather office had dispatched a team of experts to Mungeshpur after an AWS deployed there recorded a maximum temperature of 52.9 degrees Celsius on May 29 to examine the device for errors, if any.

New Delhi: Three days after a Delhi weather station hit the headlines for registering a temperature of 52.9 degrees Celsius, the India Meteorological Department (IMD) on Saturday said the instrument at Mungeshpur was a faulty one that recorded three degrees higher temperature.

“The temperature sensor of AWS Mungeshpur is found to report about three degrees Celsius higher maximum temperature than the maximum temperature reported by the standard instrument. The maximum temperature reported by the automatic weather station Mungeshpur is not correct due to malfunctioning of the sensor,” the IMD said in a statement.

The clarification comes in the wake of two AWS in Nagpur reporting 54.4 degrees and 52.2 degrees Celsius maximum temperatures earlier this week. Following a check by IMD Pune, the met agency said they found that both the Nagpur instruments were faulty, spewing out wrong data.

In the case of Mungeshpur at north west Delhi, IMD chief Mrutyunjay Mohapatra said a simple lowering of the figures by three degrees to bring down the maximum temperature to 49.9 degrees Celsius, would also not be right as the sensor was wrong. The met agency would not be using the Mungeshpur data till the instrument is replaced.

Mohapatra said IMD would be inspecting other AWS in Delhi National Capital Region that are also generating over 48 degrees or 49 degrees Celsius temperature.

“On May 29, Mungeshpur's AWS reported a temperature of 52.9 degrees Celsius, our IMD team quickly investigated and found a three degrees Celsius sensor error. Corrective measures are now in place,” Kiren Rijuju, Union Minister for Earth Sciences said in a social media post.

Temperature over urban areas varies from place to place due to local exposure such as proximity to water bodies, barren land, concrete and dense urban clusters and green areas.

IMD officials said that the maximum temperature in Delhi NCR is being monitored through five surface observatories and automatic weather stations.

The observations of maximum temperature on May 29, were between 45.2 to 49.1 degrees Celsius except Mungeshpur, which reported a maximum temperature of 52.9 degrees C.

The expert team checked the authenticity of the temperature reported at Mungeshpur by comparing it with standard instruments on May 29-30 at the site. It is found that there is a positive bias in reported temperature. The bias varies during the day turns out to be the maximum around the time of occurrence of maximum temperature.

“The temperature recorded by AWS was higher by 3.1 degrees Celsius during the time of occurrence (1515 hours IST) of maximum temperature. But a comparison of maximum temperature reported by AWS stations at other locations with departmental manual surface observatories in Delhi showed no significant difference,” said the IMD