2015 Was the Hottest Year on Record, by a Stunning Margin

We actually broke the record for breaking records.

Seven billion people seek respite from the heat.

Photographer: Dado Galdieri/Bloomberg

To say that 2015 was hot is an understatement. The average recorded temperature across the surface of the planet was so far above normal that it set a record for setting records. 

The year was more than a quarter of a degree Fahrenheit warmer than the last global heat record—set all the way back in 2014—according to National Oceanic and Atmospheric Administration figures released on Wednesday. A quarter of a degree may not sound like much, but on a planetary scale it's a huge leap. Most previous records were measured by hundredths of a degree.

A powerful El Niño is largely responsible for the year’s extremes, but make no mistake: This is what global warming looks like. Temperatures are rising 10 times faster than during the bounce back from the last ice age. Fifteen of the hottest 16 years on record have come in the 21st century. This animation shows earth’s warming climate, recorded in monthly measurements from land and sea dating back to 1880. Temperatures are displayed in degrees above or below the 20th century average.


The heat during 2015 was relentless. Monthly records were broken for every month except January (second hottest) and April (third hottest), according to data from NOAA. The year ended with an exclamation point in December, recording the most extreme departure for any month on record.

Results from the world’s top monitoring agencies vary slightly, but NASANOAA, the Japan Meteorological Agency, and the U.K.'s Met Office all agree: 2015 was unprecedented. The heat was experienced differently around the world, but most regions were unusually warm to downright scorching for much of the year.

world map
Source: NOAA

Up Next: More Broken Records

The El Niño weather pattern of 2015 produced some of the hottest temperatures ever witnessed across swaths of the equatorial Pacific. Across the globe, El Niño triggered powerful typhoons, spoiled cocoa harvests in Africa, and contributed to vast fires in Indonesia. California is getting pummeled with floods, and residents on the U.S. East Coast are bracing for an El Niño fueled snow dump this weekend.

El Niño has peaked but may carry on through late spring or early summer, according to the U.S. Climate Prediction Center. The heat that is dispersed into the atmosphere during an El Niño can linger, which means 2016 could be yet another record hot year worldwide. That's by no means guaranteed. 

The current El Niño has been a bit unusual in that it seemed to start in 2014 before faltering and re-emerging in 2015, said Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research in Boulder, Colo. As a result, the warming that typically comes after an El Niño may have already occurred, Trenberth said. "If I had to guess, 2015 will probably beat out 2016."

So 2016 might set another record. Or it might not. But one thing is certain: It won't be normal. Those days are behind us.

A Brief History of Global Warming