Temperatures at the Persian Gulf International Airport in Asaluyeh, Iran, climbed to 108 on Wednesday and 106 on Thursday, with both days recording a peak heat index of 149. In Dubai, the temperature topped out at 113 on Tuesday and the heat index soared to 144. Other extreme heat indexes in recent days include 141 in Abu Dhabi and 136 at Khasab Air Base in Oman.
Last August, this same region experienced even more extreme heat indexes, climbing as high as 158 degrees.
The maximum air temperatures this week — generally between 105 and 115 — have only been somewhat above normal. But the dew points — which are a measure of humidity — have been excessive, climbing well into the 80s. In the United States, any dew point over 70 degrees is considered uncomfortably humid.
It’s the very high dew points that have propelled heat indexes up to 30 degrees above actual air temperatures.
The extreme humidity levels are tied to bathtub-like water temperatures in the Persian Gulf, the warmest in the world. According to National Oceanic and Atmospheric Administration data, sea surface temperatures are as warm as 95 degrees.
Largely because of the high humidity, nighttime minimum temperatures have also remained exceptionally warm, in many cases staying above 85. Temperatures in Iranshar, Iran, only dropped to 97 on Wednesday night, its hottest July night on record.
A Washington Post analysis found that the wet-bulb globe temperature, which measures the amount of heat stress on the human body, reached 96 at the Persian Gulf International Airport and 95 in Dubai, exceeding the threshold of 89.6 that researchers have said poses a risk to human survival if such heat is prolonged. The wet-bulb globe temperature, which was calculated using data from nearby weather stations, takes into account a combination of temperature, humidity, wind and clouds.
Researchers have identified the Persian Gulf among the regions most likely to regularly exceed life-threatening heat thresholds during the next 30 to 50 years. Dubai was recently ranked as the city having the most dangerous summer heat in the world, with dangerous heat on 89 percent of summer days. Doha, Qatar, came in second.
There were also numerous heat records in the same region last week, according to weather historian Maximiliano Herrera. The United Arab Emirates saw a scorching high temperature of 123 while Adrar, Algeria, tied its all-time record of 122. Cities in both Kuwait and Iraq reached 126, and Al Ahsa, Saudi Arabia, notched an all-time record of 124. The city of Amarah recorded Iraq’s warmest nighttime low on record at 102.
The exceptional heat and humidity is the result of a sprawling area of high pressure called a heat dome, extremely warm water temperatures and human-caused climate change.
The same heat dome has spread record heat northward into Eastern Europe, westward into northern Africa, and eastward into India, Pakistan and Indonesia. In Eastern Europe, high temperatures surpassed 104 with some locations staying above 85 degrees at night. The temperature in Algeria hit 122.
It was so hot in Greece on Wednesday that officials closed the Acropolis for five hours, according to the Associated Press.
The intense July heat comes after the temperature reached 125 in Saudi Arabia in June, leading to hundreds of deaths from heatstroke during the Hajj pilgrimage. Also in June, nighttime temperatures remained as high as 95 in Delhi on June 18.
Dangerous, record-setting heat swept across five continents in June, which was Earth’s hottest June on record according to the NOAA. Scientists say the heat waves show how human-caused climate change has made life-threatening temperatures more common.
Jason Samenow contributed to this report.
