Are you still wearing shorts and T-shirts? If you say yes, there's a good reason.

你现在还穿着T恤和短裤吗？如果是，倒也不奇怪。

Planet Earth has definitely experienced its hottest summer since detailed records have been kept, and according to scientists, it might have been the hottest in more than 4,000 years.

The meteorological summer of June-July-August in the Northern Hemisphere saw its highest globally averaged temperature since records began in 1880, the National Oceanic and Atmospheric Administration (NOAA) reported.

Seven out of the nine months this year have made their way to the record books. Now that it's fall, September saw its highest temperature on record, for land and ocean surfaces.

What do scientists point to for this phenomenon?

"The unprecedented heat continues to be driven by the strong El Niño in the Pacific," said CNN senior meteorologist Dave Hennen. "We're now five months in a row of record highs, and that will likely continue with El Niño forecast to last well into the spring."

Climate research suggests these are the hottest temperatures the Earth has seen since the Bronze Age.

The report also said record heat was reported across northeastern Africa stretching into the Middle East, part of southeastern Asia, most of the northern half of South America, and parts of central and eastern North America.