For centuries, tales have circulated about scorching locales, whispered legends of places so intensely hot they defy belief. One such place is the Flaming Mountain in China, a fiery ridge rumored to reach a staggering 80°C (175°F) in the summer, marked by a towering golden thermometer as a testament to its supposed extreme heat. But is local lore always accurate? And Where Is The Hottest Place On Earth, really?
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Local stories often point to Flaming Mountain as the hottest place. Scientists used NASA data to investigate if this was true. (Photograph ©2011 oh contraire.)
Intrigued by such claims, ecologist Steve Running and his team at the University of Montana embarked on a quest to pinpoint the definitive hottest place on Earth. Their research revealed a surprising truth: the location of Earth’s heat champion isn’t fixed, but the conditions are – think arid, rocky terrains with dark surfaces that soak up the sun’s energy.
Historically, the title of “hottest place on Earth” based on recorded air temperature has been fiercely contested. Death Valley in California, specifically Furnace Creek, famously registered 56.7°C (134°F) in July 1913. However, this record was challenged just nine years later when El Azizia, Libya, reportedly hit 58.0°C (136.4°F) in September 1922. The World Meteorological Organization (WMO) still recognizes the El Azizia reading as the highest air temperature ever officially measured, although its validity has been questioned by some experts.
“Many places touted as the hottest on Earth are not even in the running,” explains Running. This discrepancy arises partly from measurement methods and locations. To truly understand where the hottest place on earth is, we need to delve deeper into how temperature is measured and consider the limitations of ground-based weather stations.
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Weather stations (black dots) are sparse in the world’s hottest and most remote areas. Satellites offer a comprehensive view to fill in the gaps. (Map by Robert Simmon, using data from the WMO & Natural Earth.)
David Mildrexler, another researcher from the University of Montana, highlights the scarcity of weather stations in the regions most likely to experience extreme heat. “The WMO operates approximately 11,119 weather stations across Earth’s land surface,” he notes. “But when you consider the vast 144.68 million square kilometers of land, that’s only one station per 13,012 square kilometers.”
He further elaborates, “The Earth’s scorching deserts—like the Sahara, Gobi, Sonoran, and Lut—present incredibly harsh climates and are so remote that setting up and maintaining weather stations for routine measurements becomes incredibly challenging. Consequently, many of Earth’s true hottest spots simply aren’t being directly monitored by instruments on the ground.”
This is where the power of satellite technology becomes indispensable in the search for the hottest place on earth.
For over a decade, NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS), aboard the Terra and Aqua satellites, has been diligently scanning the globe. MODIS boasts 36 spectral bands, enabling it to observe Earth in numerous ways, including detecting thermal radiance—the infrared energy emitted from the land surface. With its capacity to scan the entire planet daily, MODIS provides a comprehensive thermal map, effectively bridging the data gaps left by ground-based stations in the quest to locate the hottest place on earth.
Understanding What “Hottest” Truly Means
Have you ever heard the phrase, “it’s a hundred degrees in the shade“? This common saying inadvertently points to a crucial aspect of temperature measurement.
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Direct sunlight significantly heats surfaces beyond air temperature. In winter, shaded areas were 40–46°F (4.0–8.0°C), while sunny areas reached 56–66°F (13–19°C), even when the air was 54°F (12°C). (NASA photograph by Robert Simmon.)
Air temperature measurements, to be accurate, must be taken out of direct sunlight. Why? Because thermometers and their surroundings can absorb solar radiation, skewing the heat readings. You experience this phenomenon personally – standing in direct sunlight makes you feel warmer due to both air temperature and radiant solar energy heating your skin.
To adhere to the World Meteorological Organization standards (PDF) for air temperature readings, a thermometer must be positioned 1.2 to 2 meters above the ground and shielded from direct sunlight. However, it also cannot be placed in the shade of structures like buildings, mountains, or trees, ensuring a true ambient air temperature reading.
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Accurate air temperature readings require thermometers shielded from direct sunlight, often housed in Stevenson screens. (Photograph ©2006 Richard Allaway.)
MODIS, however, measures something fundamentally different: Land Surface Temperature (LST). LST quantifies the heating of the Earth’s surface – where solar energy is absorbed and re-emitted. Crucially, LST is often considerably hotter than air temperature. Think about walking barefoot on a scorching summer day. The pavement burns your feet, far hotter than the air you breathe. This stark difference highlights the distinction between air temperature and land surface temperature, vital when searching for the hottest place on earth.
Scientists recognized this difference early on. Around the time of Death Valley’s record air temperature in 1915, researchers in the Arizona desert near Tucson analyzed both air and soil temperatures. At midday, the soil temperature just 0.4 centimeters beneath the surface reached a blistering 71.5°C (160.7°F), while the air temperature, measured four feet above ground, was a comparatively cooler 42.5°C (108.5°F).
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Dark pebbles contribute to the Lut Desert in Iran being recognized as the hottest place on Earth based on land surface temperature. (Photograph ©2005 Jafar Sabouri, Geological Survey of Iran.)
Air temperatures are moderated by atmospheric circulation – vertical air movement and horizontal winds. Moisture content also plays a role in regulating heat retention in the air. “Air temperature measurements are valuable because they reflect what humans, buildings, and ecosystems experience,” explains Stuart Gaffin, a climate researcher at Columbia University and NASA’s Goddard Institute for Space Studies. “Air temperature largely dictates our thermal comfort.”
Conversely, land surface temperatures represent the direct heating of the ground by solar radiation, atmospheric heat, and other heat fluxes. The highest LSTs are therefore expected in areas with clear skies, dry soil, and minimal winds. The land surface composition is also critical. Optimal conditions for extreme LST involve surfaces that absorb most sunlight (low albedo), reflect little, and are poor conductors of heat. Rocky deserts perfectly embody these characteristics, making them prime candidates for the hottest place on earth.
Satellite image of the Turpan Depression near the Flaming Mountain, China.
Map of temperatures in the Turpan Depression near the Flaming Mountain, China.
The darker Shanshan dune field absorbs more sunlight than the adjacent Flaming Mountain, resulting in higher surface temperatures in the Turpan Depression. (NASA images by Jesse Allen and Robert Simmon, using Landsat 7 data from USGS Global Visualization Viewer.)
Running, Mildrexler, and Zhao meticulously analyzed global MODIS LST data from 2003 to 2009, focusing on areas where the highest satellite-measured temperatures coincided with ideal terrain. “To pinpoint the hottest place on Earth,” Mildrexler explains, “we concentrated on barren and sparsely vegetated areas, such as open shrublands.”
Their analysis consistently pointed to a few key locations: the Lut Desert in Iran, the arid landscapes of Queensland, Australia, and, indeed, the Flaming Mountain region.
Where Is the Hottest Place on Earth?
Seven years of satellite temperature data revealed the Lut Desert in Iran as the most consistently hottest place on Earth. It was the hottest location in 5 out of 7 years, reaching a peak of 70.7°C (159.3°F) in 2005. (NASA maps by Jesse Allen and Robert Simmon, using MODIS data from Mildrexler et al., 2011.)
Over seven years of satellite data, the Lut Desert emerged as the most consistently hottest place on earth. In five of those years (2004, 2005, 2006, 2007, and 2009), it recorded the highest surface temperature globally. The absolute highest LST recorded during this period was in the Lut Desert in 2005, a scorching 70.7°C (159.3°F)—over 12°C (22°F) hotter than the official air temperature record from Libya.
However, the Lut Desert wasn’t the hottest every single year. In 2003, Queensland, Australia, reached 69.3°C (156.7°F), the second-highest in the seven-year study. And in 2008, the Flaming Mountain area, specifically the Turpan Basin, claimed its share of extreme heat with a yearly maximum of 66.8°C (152.2°F).
The Significance of Land Surface Temperature
Understanding land surface temperature is more than just academic trivia. LST is directly linked to how humans modify the land.
Climatologist Roger Pielke Sr. from the Cooperative Institute for Research in Environmental Sciences at the University of Colorado notes, “The highest temperatures were found in areas lacking vegetation. This means that landscape changes causing vegetation loss in a region will likely result in hotter maximum surface temperatures. Conversely, developing an oasis in a desert through irrigation would reduce maximum temperatures.”
The Pacific Northwest region of the United States provided Running, Mildrexler, and Zhao with an excellent case study. “The Pacific Northwest exhibits a remarkable ecological and temperature gradient, transitioning from coast to rainforest to desert within a few hundred miles,” Running explains. This region perfectly illustrates the relationship between land cover and its ability to absorb and radiate heat, impacting the hottest place on earth in localized contexts.
Natural-color satellite image of the Pacific Northwest.
Map of daytime surface temperatures in the Pacific Northwest.
Satellite images of the Pacific Northwest reveal the link between landscape characteristics and day/night surface skin temperatures. Densely forested areas remain cooler than barren, arid regions which can be significantly hotter. Images captured in the early morning and afternoon of July 6, 2011. (NASA images by Jesse Allen and Robert Simmon, using MODIS data.)
In coastal, densely forested areas, LST and air temperature are closely aligned. Trees, with their deep roots, access soil moisture and cool themselves through transpiration. Moving eastward into farmland and grasslands, where soil moisture is less available during hot periods and plant roots are shallower, the temperature gap widens. Finally, the inland rocky deserts experience extreme heating during the day, and conversely, dramatic cooling at night, demonstrating the significant impact of land cover on surface temperatures and influencing what could be considered the hottest place on earth within a specific biome.
Mildrexler and Running suggest that long-term LST records could be a valuable tool for monitoring land cover change, particularly deforestation, urban expansion, and irrigation practices. Changes in LST over time can indicate shifts in land use.
“Forests are significantly cooler than cleared land during peak temperatures. Deforestation therefore leads to increased land surface temperatures,” they wrote in the Bulletin of the American Meteorological Society in 2011. “This effect is observable in the Amazon. Conversely, irrigated crops are cooler than natural vegetation due to increased water availability and evaporative cooling.”
LST data also reveals much about the escalating urban heat island effect. As Stuart Gaffin points out, “Surface temperatures in cities often surpass those in deserts.”
Gaffin studies the urban heat island effect—the tendency of cities to trap heat and become considerably warmer than their natural surroundings. The U.S. Environmental Protection Agency estimates that urban areas often experience air temperatures up to 6°C (10°F) higher than adjacent suburban and rural areas. This phenomenon emphasizes that the hottest place on earth in terms of human experience can very well be urban environments.
Satellite map of temperatures around Shanghai, China on July 3, 2001.
Cities, like Shanghai, are often significantly warmer than surrounding rural areas due to the urban heat island effect, caused by dark surfaces and reduced vegetation. (Map by Jesse Allen and Robert Simmon, using Landsat 7 data from USGS Global Visualization Viewer.)
The spatial resolution of most satellite sensors is too coarse to capture the intricate LST variations within cities. The University of Montana study, for example, used LST data with a resolution of roughly 5.6 square kilometers. At this scale, city pixels include shadows from buildings and vegetation, leading to lower average LST readings compared to uniformly hot deserts.
To overcome this, Gaffin utilizes portable infrared radiometers to measure surface temperatures in New York City. He has recorded LSTs on black tar rooftops reaching 77 to 82°C (170 to 180°F) in mid-summer. These superheated rooftops exacerbate summer heat by radiating extra warmth day and night. Even in winter, rooftop temperatures can be significantly warmer than ambient air temperatures. This highlights how urban structures can create localized “hottest place on earth” scenarios.
Satellite image of Con Edison building, Long Island City, New York.
Urban temperatures can rival the hottest deserts. Sensors on the Con Edison building in Queens, NY, compare surface temperatures of black, white, and green roofs. Black roofs can be 30°C (54°F) hotter than green or white roofs. (Images by Robert Simmon, using data ©2010 DigitalGlobe and Columbia University Center for Climate Systems Research.)
Gaffin focuses on mitigating heat concentration on rooftops and other impervious urban surfaces by increasing reflectivity. New York City has over 77 square kilometers (30 square miles) of tar rooftops, effectively “tar beaches.” Furthermore, the increasing use of synthetic turf fields, while visually resembling grass, lacks the crucial evaporative cooling properties of natural grass, leading to surface temperatures approaching skin-burning levels, akin to black pavement. These urban design choices directly influence the hottest place on earth experience within cities.
Gaffin and his colleagues have dedicated nearly a decade to developing solutions to combat urban heat islands and reduce LSTs in cities. Simple measures like painting rooftops white or implementing low-maintenance green roofs can significantly reduce urban heat. This is crucial for energy conservation and improving urban quality of life. Elevated LSTs drive up air temperatures, forcing cities to expend more energy and resources on cooling.
Photograph of the green roof on top of the Con Edison building, Long Island City, New York.
Green roofs, and even simple white roof coatings, are effective techniques to combat the urban heat island effect and reduce temperatures significantly. This image shows the green roof and instrumentation on the Con Edison building in Queens. (Photograph ©2008 Con Edison of New York.)
“Approximately 3.5 billion people now reside in cities,” Gaffin emphasizes. “We face the combined challenges of urban heat islands and global warming, creating increasingly extreme conditions for over half the world’s population. The critical question is: how can we make cities more habitable in the future?” Addressing urban heat and understanding the hottest place on earth, both in natural and built environments, is paramount to ensuring a sustainable and comfortable future for urban populations globally.
