July 2019, marked by persistent, historic heat waves, was the warmest month ever observed in 140 years of record-keeping, according to new data from the National Oceanic and Atmospheric Administration (NOAA).

NOAA's confirmation of the hottest-recorded month follows similar conclusions from both European Commission analysis and the climate research organization Berkeley Earth.

"Much of the planet sweltered in unprecedented heat in July, as temperatures soared to new heights in the hottest month ever recorded," the agency wrote. "The record warmth also shrank Arctic and Antarctic sea ice to historic lows."

Because July is typically the warmest month of the year on Earth, a record-breaking July would likely mean the warmest month ever recorded, explained Deke Arndt, chief of the monitoring section for NOAA's National Centers for Environmental Information, in a call with reporters. This certainly turned out to be true for July 2019.

"With all the record heatwaves around the globe this summer, it’s not surprising that July 2019 has turned out to be the warmest July globally on record," Jon Overpeck, a climate scientist at the University of Michigan, said over email. "Very few countries avoided warmer or much warmer than normal temperatures, and record warmth impacted a surprising number of regions.

"Global warming continues to bake our planet more and more," Overpeck, who had no role in the NOAA report, added.

Climate extremes in July 2019 Image: Noaa

July 2019 was remarkable in breaking an all-time record, but it also perpetuates a stark long-term trend. "This is the 415th consecutive month warmer than the 20th-century average," Arndt noted. This means that anyone born after 1985 has never experienced a month of average weather.

Though significant swaths of the Lower 48 states experienced either normal or cooler-than-average temperatures (particularly the Northwest and large portions of the Plains), twice as many daily warm records were set as cold records in the contiguous states.

"This is the 415th consecutive month warmer than the 20th century average."

"Much of the U.S. was lucky to have more normal July temperatures, but the Northeast, and especially Alaska were hit hard by anomalous heat," noted Overpeck.

Matters were certainly extreme in Alaska, the nation's fastest-changing state. July was the warmest month in the state's history, with all-time record high temperatures toppling across the northern state. Hot temperatures mean conditions ripe for fire. Some 2.44 million acres have burned in Alaska this season, an area nearly twice the size of Delaware, noted Rich Thoman, a climate specialist with the Alaska Center for Climate Assessment and Policy at the University of Alaska Fairbanks. This isn't nearly record-breaking, but part of a trend in increased Alaskan wildfire.

Most regions of the Earth, including both land and ocean, were above average in July 2019. Warmth was particularly significant in Alaska, Greenland, Europe, Africa, and parts of Asia and Antarctica.



A few area, e.g. Western Russia and parts of Antarctica, were unusually cold. pic.twitter.com/esl0SB3MOi — Robert Rohde (@RARohde) August 15, 2019

This July, which was globally 1.71 degrees Fahrenheit above the 20th-century average, helped perpetuate a significant decline in Arctic sea ice: "Average Arctic sea ice set a record low for July, running 19.8% below average — surpassing the previous historic low of July 2012," NOAA concluded.

2019 is now "virtually certain" to be one of the top five warmest years on record, explained NOAA's Arndt. Already, each of the last five years have been the five hottest years on record.