Last month was the warmest June on record, according to researchers at the National Oceanic and Atmospheric Administration's National Centers for Environmental Information.
June temperatures measured 1.62 degrees Fahrenheit over the 20th century average, the NOAA said in a news release on Tuesday.
Also on Tuesday, NASA said that both global surface temperatures and the Arctic sea ice extent had "broken numerous records" in the first six months of 2016.
The period between January and June was the world's hottest six months on record, 2.4 degrees Fahrenheit warmer than the end of the 19th century, NASA stated.
"While the El Niño event in the tropical Pacific this winter gave a boost to global temperatures from October onwards, it is the underlying trend which is producing these record numbers," Gavin Schmidt, director at NASA's Goddard Institute for Space Studies, said in a statement on the agency's website.
NASA added that, compared to the late 1970s and early 1980s, the extent of Arctic sea ice during the height of the "summer melt season now typically covers 40 percent less area."
"It has been a record year so far for global temperatures, but the record high temperatures in the Arctic over the past six months have been even more extreme," NASA's Walt Meier said. "This warmth as well as unusual weather patterns have led to the record low sea ice extents so far this year," Meier added.
NASA says its scientists are currently studying sea ice melt in the Arctic and how an increase in temperatures is impacting ecosystems there.