2015 goes into the books as the warmest year the Earth has experienced since 1880, when official records began. And the record was not merely set, but shattered.
Combining land and ocean surface temperatures, the global average for the year was 1.62°F (0.9°C) above the 20th century average, according to data gathered by federal climate scientists.
The extreme temperatures were evenly distributed worldwide and part of the "long-term trend," says Gavin Schmidt of NASA's Goddard Institute for Space Studies, and would have been unprecedented even without the warm El Niño conditions that have prevailed in the Pacific Ocean for much of the year.
Both sea and land temperatures set new highs individually, but land temperatures in particular were way out into record territory, surpassing the previous record of 2007 by 0.45°F (0.25°C).
It's the fourth time since 2000 that the global temperature record has been broken. Only two months -- January and April -- did not set temperature records globally, the first time that 10 months of any given year have all set high-temperature marks.