New data shows the Earth recorded its warmest-ever temperature for the June-to-August period.
The U.S. National Oceanic and Atmospheric Administration says the world-wide average temperature for the three-month period was 16.4 degrees Celsius. That is 0.71 degrees Celsius higher than the previous record set in 1998, and the highest since the records were first kept in 1880.
The world's oceans were particularly warm in August, 0.65 degrees Celsius above the average for the month and topping the record set in June.
The Earth could be on track to its warmest year ever. If the last four months of the year record temperatures among their highest ever, 2014 will replace 2010 as the globe's hottest ever.
The U.N. Climate Summit is set to convene Tuesday, with the meeting aimed at pushing the world's nations toward a new global climate treaty by the end of 2015.