Last month was the hottest August in modern times and marked the 16th month in a row when global records for heat were shattered planet-wide, US authorities said Tuesday.

The string of unusual heat across land and sea surfaces is "the longest such streak in the 137-year record," said the monthly climate report by the National Oceanic and Atmospheric Administration.

The NOAA report also found that global temperatures over the entire year so far have been "the highest on record."

Average temperature for the year across global land and ocean surfaces was 1.82 degrees Fahrenheit above the 20th century average of 57.3 F.

That was enough to surpass 2015, the previous record holder, by 0.29 F.

Climate scientists say the upward trend of heating is driven by the burning of fossil fuels, which add to greenhouse gases that trap heat around Earth.

The record heat trend has been exacerbated by the El Nino weather phenomenon, which boosted warmth in the Pacific around the equator in the first half of this year.

A separate analysis issued by NASA's Goddard Institute for Space Studies (GISS) on September 12 found that last month tied with July's record for the hottest month ever in the modern era.

"Monthly rankings, which vary by only a few hundredths of a degree, are inherently fragile," GISS director Gavin Schmidt said in a statement.

"We stress that long-term trends are the most important for understanding the ongoing changes that are affecting our planet."

- August records -

Taken alone, August's temperature across global land and ocean surfaces was 1.66 degrees Fahrenheit above the 20th century average of 60.1 F, NOAA reported.

"This was the highest for August in the 1880-2016 record, surpassing the previous record set in 2015 by 0.09 F," the government agency said.

Africa and Asia each saw record-high average temperatures for the month -- the hottest since continental records began in 1910.

"Much-warmer-than-average conditions engulfed the vast majority of the world's land surfaces," said the NOAA report.

"Record warmth during the first eight months was present across Alaska, western Canada, northern South America, central and southern Africa, southern Europe, Indonesia, and across parts of Central America, the Caribbean, northern and central Asia and Australia."

Bahrain experienced its second-warmest August since national records began in 1902, with an average temperature of 97.5 F -- or 4.3 F above average.

New Zealand has seen its hottest year since national records began in 1909.

- Hot water -

The world's oceans, which absorb much of the heat from the atmosphere, were the second-warmest on record, just a tad (0.04 F) behind 2015.

Record warmth was observed in the Atlantic along the US East Coast, the central southern Atlantic Ocean, and across parts of the western Indian Ocean and the western and southeastern Pacific Ocean, said NOAA.

"Cooler-than-average conditions were limited to small areas" of the Pacific, the southern Atlantic Ocean and the southeastern Indian Ocean.

The warming trend of El Nino subsided in July and neither El Nino nor La Nina, its cooling counterpart, are expected to prevail for the rest of this year.

In another troubling indicator for the planet, sea ice in the Arctic continued to retreat.

"The average Arctic sea ice extent for August was 23.1 percent below the 1981-2010 average," said NOAA.

"This was the fourth-smallest August extent since records began in 1979."