A reading of 56 degrees Celsius at an automatic weather station in Nagpur was likely erroneous due to a sensor malfunction in extreme heat.
India’s Regional Meteorological Centre said on Friday, the second instance when such stations have triggered alarm. Experts said the problem can be rooted in a variety of factors, including the devices, how they are placed and their calibration.
“Automatic systems may report erroneous readings due to various factors such as site conditions, damage of sensors or its protection shields,” the RMC in Nagpur said in a statement, adding that the May 30 reading was an outlier and not correct.
A station in Delhi, Mungeshpur, recorded 52.3°C on Wednesday, but the India Meteorological Department (IMD) said it is verifying that record.
“Some of our scientists are telling us that automatic sensors can malfunction in very high temperatures or extreme weather,” said M Mohapatra, IMD director general. “We are studying all aspects of these records, the location, the machine, everything.”
Mahesh Palawat, vice president of climate and meteorology at Skymet Weather, said erroneous readings can happen if an automatic weather station is not calibrated for an extreme temperature range and its location is a factor.
Heat wave to severe heat wave conditions prevailed Friday over many parts of north and central India, with maximum temperatures reaching 47-48°C in multiple locations, according to IMD. It issued an orange alert, the second-highest level, for northwest, central and east India on June 1.
Maximum temperatures are closing in on 50° C. For example, on Friday, Delhi’s Ayanagar recorded 47°C; Kanpur IAF 48.2°C; Bhatinda airport 47.6°C; Titilagarh in Odisha 46.5°C; Sirsa in Haryana 47.8°C. Warm night conditions observed in pockets of Rajasthan, Uttar Pradesh, Bihar, Jharkhand, Odisha and Madhya Pradesh on Thursday.
Despite the long heat wave spells, there is no official record of heat-related deaths in India this year. The home ministry’s disaster management division, which tracks deaths and losses from extreme weather, did not respond to questions about the toll.
Notably, there are 813 automatic weather stations in the country.