The US experienced its warmest ever June last month, with a scorching summer set to compound a string of climate-related disasters that have already claimed dozens of lives and cost billions of dollars in damage this year.



Worldwide, heat records have been broken for 13 months in a row, an unprecedented streak of warmth that has stunned climate scientists and heightened concerns over the future livability of parts of the planet.

The average temperature for the contiguous US was 71.8F (22.1C) in June – a full 3.3F (1.8C) above the 20th-century average and breaking a record set in 1933. According to the National Oceanic and Atmospheric Administration (Noaa), the first six months of 2016 have been the third warmest on record in the US.

Drought conditions “remain entrenched across much of California” according to Noaa, with 16% of the contiguous US in drought – up 3.5% compared to May.

The US has already suffered a number of climate- and weather-related calamities in 2016, with Noaa recording eight events that have each cost at least $1bn in damages. More than 30 lives have been lost in disasters including flooding in Texas, tornadoes across the south-east and wildfires in the west.

A chart highlighting the rise of billion-dollar disaster events in the US. Photograph: NOAA

The figures don’t including recent flooding in West Virginia that has claimed the lives of 23 people and wrecked more than 1,200 homes.

“How much more record heat and how many more unprecedented extreme weather disasters must be witnessed before we all recognize this simple fact: climate change is real, it is human-caused, and it is already posing an extreme risk to us and the planet,” Michael Mann, a leading climatologist at Penn State University, told the Guardian. “The good news is that there is still time to act to avert the most dangerous impacts. But not a whole lot of time.”

Much of the US is currently sweltering in a heatwave, with New York, Connecticut and Virginia set to experience at least three consecutive days over 90F (32C). Boston, Philadelphia and Washington have already experienced temperatures above 90F, with southern states basking in temperatures significantly above average. Heat warnings have been issued in cities including New Orleans and Macon, Georgia.

This year is almost certain to be the warmest on record globally, beating a mark set in 2014 and then again in 2015. The chances of three record-breaking years of heat without climate change induced through the burning of fossil fuels is about one in a million, according to Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany and colleagues.