Shockingly high temperatures in October all but guarantee that 2015 will be the world's hottest year ever recorded.
Last month was the warmest October ever recorded -- and the sixth straight month to set record temperatures. It also was the first month to surpass the average temperature by more than 1 degree Celsius, new NASA data revealed Tuesday.
October was 1.04 degrees Celsius, or about 1.87 degrees Fahrenheit, hotter than the base period of 1951 to 1980 used as a reference to measure the long-term average, NASA's Goddard Institute for Space Studies reported. That marks the greatest departure from a month's average heat since weather record-keeping began in 1880, beating January 2007 as the most anomalous month by 0.07 degrees Celsius.
October's heat means there's a 99.9 percent chance that 2015 will claim 2014's title as the hottest year on record, GISS director Gavin Schmidt tweeted.
Surpassing the 1-degree mark is significant, The Washington Post notes, because it puts the Earth halfway to the "internationally accepted limit for avoiding the worst consequences of climate change," such as drought, mass migration and superstorms. Putting a stop to climate change before it reaches the 2-degree milestone is the main goal of the Paris Climate Summit kicking off Nov. 30.
October's heat comes in a banner year of record-breaking weather events. July was the hottest month ever recorded. In the United States this year, Florida recorded its hottest March to May. California, Idaho, Oregon, Utah and Washington all logged their hottest Junes.
CORRECTION: A previous version of this post misstated the day the Paris Climate Summit will start.
Also on HuffPost: