Research Features

Extreme Heat for an Extreme Year

Warm weather is expected in the summer, but the oppressive heat that affected several parts of the world in 2016 went well beyond warm. In June and July, people living in Siberia, the Middle East, and North America faced extreme heat waves.

Extreme Heat for an Extreme Year

Acquired July 20-27, 2016 — Download large image (3 MB, JPEG, 2400x2400)

Parts of Siberia where cool weather usually lingers even during summer saw temperatures that would have been more fitting in the tropics. In July, a rare outbreak of anthrax even emerged in the Yamal Peninsula after hot weather melted permafrost and exposed the carcass of a reindeer. Since the outbreak began, the bacteria has killed one child and more than 2,300 reindeer.

Meanwhile, on July 21, 2016, as an intense heat wave gripped the Middle East and Southwest Asia, a weather station in Mitrabah, Kuwait, recorded a temperature of 54.0 degrees Celsius (129.2 degrees Fahrenheit) — possibly the highest temperature on record for the Eastern Hemisphere and Asia. A committee of World Meteorological Organization experts is investigating whether the sensor used to make the measurement is reliable before declaring the record officially broken.

Acquired July 20-27, 2016 — Download large image (3 MB, JPEG, 2880x1920)

As parts of the Eastern Hemisphere baked, parts of the Western Hemisphere saw streaks of hot weather as well. In June, record-breaking heat scorched the southwestern United States. In July, several cities in the Southwest and Southeast broke monthly temperature records. For two states — Florida and New Mexico — July 2016 proved to be the hottest July on record. During the peak of one heatwave in the United States, some 124 million people were under extreme heat warnings, according to the National Weather Service.

The three maps here show land surface temperature anomalies in Russia, the Middle East, and North America from July 20–27, 2016, compared to temperatures for the same dates from 2001 to 2010. The anomalies are based on land surface temperatures observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Red areas were hotter than the long-term average by as much as 12 degrees Celsius (22 degrees Fahrenheit) in some places; blue areas were below average. White pixels had normal temperatures, and gray pixels did not have enough data, most likely due to excessive cloud cover. Oceans and lakes appear in gray.

Acquired July 20-27, 2016 — Download large image (1 MB, JPEG, 1600x1600)

Note that land surface temperatures are not the same as air temperatures. Instead, they reflect the heating of the land surface by sunlight, and they can sometimes be significantly hotter or cooler than air temperatures. (To learn more about land surface temperatures and air temperatures, read: Where is the Hottest Place on Earth?)

The bouts of heat come amidst an unusually hot year globally. The six-month period from January to June was the warmest half-year on NASA’s global temperature record, with an average temperature that was 1.3 degrees Celsius (2.4 degrees Fahrenheit) warmer than the late nineteenth century. This follows 2015, which was the warmest year on record and among the warmest decade on record. The ongoing warming trend — as well as the increasing frequency and severity of high-humidity heat waves — is ultimately driven by rising concentrations of carbon dioxide and other greenhouse gases in the atmosphere.

“While people are very interested in records — the warmest, the hottest, the driest, the wettest — what really matters for how people live and how ecosystems function are the long term trends and the shift in the whole distribution toward warmer temperatures,” said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, on KCRW’s To the Point. “The most important thing to remember is that this is part of a long-term trend. We’re not [just] talking about a one-off temperature record. We’re talking about whole stretches of time in India, Pakistan where it’s above 50 degrees Celsius (122 degrees Fahrenheit).”

Further Reading

NASA Earth Observatory images by Jesse Allen based on data from the Land Processes Distributed Active Archive Center. Caption by Adam Voiland.

This article was originally prepared as an Earth Image of the Day for the NASA Earth Observatory.