Iran village hits dangerous 82.2°C heat index

If confirmed, the heat index and a corresponding dew point of 36.1°C could be among the highest such readings ever recorded on the planet

New Delhi: A village off the southern coast of Iran may have hit dangerously high temperatures this week, with the weather station at the Dayrestan Airport recording a heat index of 82.2°C on August 28.

An Iranian taxi driver splashes water on himself to cool down during the heat surge in Tehran, Iran, on July 21. (REUTERS)

If confirmed, the heat index and a corresponding dew point of 36.1°C could be among the highest such readings ever recorded on the planet.

According to records maintained by the US’s National Weather Service, which collates data from the METAR (the aerodrome routine meteorological report used by aviation pilots and meteorologists) Global readings, the Dayrestan Airport weather station recorded a temperature of 38.8°C at 10.30am on August 28.

Viewed alone, the temperature isn’t as alarming. But, with a relative humidity of 85%, it combines to give the HI, or “feels like” temperature, of 82.2°C.

Typically, higher temperatures are recorded in arid regions, where the humidity is likely to be lower. The body actually feels cooler in arid conditions.

When the body gets too hot, it begins to perspire or sweat to cool itself off. When perspiration is evaporated off the body, it effectively reduces the body’s temperature. If the perspiration is not able to evaporate, the body cannot regulate its temperature. Thus, the human body feels warmer in humid conditions (at higher RH).

Prolonged exposure to a heat index between 40-54°C is associated with heatstroke.

Dew point, meanwhile, is the temperature point at which the air can hold no more water (water vapour).

While the records are yet to be verified, a heat wave has blanketed much of West Asia in recent weeks, with temperatures in the region soaring to 50°C. Similar conditions last month forced authorities to cut operating hours at various facilities and order all government and commercial institutions to close on Sunday to conserve energy, as hundreds lined up at hospitals for heatstroke treatment.

The August 28 record serves as a dire warning for the worsening conditions in the Global South, with experts predicting that heatwaves are likely to get lengthier and more frequent.

In an April 22 interview to HT, Friederike Otto, Senior Lecturer in Climate Science at Grantham Institute - Climate Change and the Environment, Imperial College London warned: “In many regions of the world, summers are becoming much hotter, increasing the risk of heatwaves, fires and droughts, as winters become much wetter, increasing the risk of devastating floods.”