Last month was the warmest June on record in North America, researchers said Wednesday, confirming the suspicions of millions of people suffering some of the hottest temperatures ever seen on the continent.

The Copernicus Climate Change Service, a European Union-backed agency, said average June surface temperatures in North America were about a quarter of a degree Fahrenheit (0.15 degrees Celsius) higher than the average for June 2012, the previous record holder.

Last month’s average temperature was more than 2 degrees Fahrenheit higher than the 1991-2020 average, which provides more evidence that human-made emissions of carbon dioxide and other heat-storing gases are warming the planet.

The June heat was relentless in most of the United States and Canada. Only parts of the Southern Plains and the southeastern United States and northern Canada east and west of Hudson Bay were slightly cooler than normal.

The most brutal conditions were experienced in the western United States and southwestern Canada. In the west, the heat prolonged and exacerbated a severe drought, shrinking crops, threatening water supplies and adding to a severe forest fire season.

The month culminated in a hell of a heat wave that crippled much of Oregon, Washington, and British Columbia.

With an enormous “heat dome” made of high pressure air that came to a standstill over the region, temperatures in Portland, Oregon, Seattle and other cities reached three-digit temperatures, 30 to 40 degrees above the monthly average. Heat-related deaths have skyrocketed in a region where air conditioning was only an afterthought until recently.

The city of Lytton, British Columbia broke the Canadian temperature record three days in a row, ending June 29 at 121 degrees. The next day, most of the city was destroyed by wildfire, in which two residents were killed.

The high temperatures last month were not limited to North America, according to Copernicus’ analysis. Europe suffered from the second warmest June ever, only June 2019 was warmer. Temperatures were above average in the northwest and southern Africa, parts of the Middle East, China and much of Southeast Asia. High temperatures in arctic Siberia contributed to an early start to the forest fire season there.

Worldwide, last month was the fourth warmest June ever. Only 2016, 2019 and 2020 were hotter.

It is likely to stay hotter than normal in the US for the remainder of the summer, according to the latest analysis by the National Oceanic and Atmospheric Administration.

Overall, according to the analysis, 2021 is almost certainly one of the 10 warmest years ever recorded. But thanks to slightly cooler conditions earlier this year coupled with cooler sea surface temperatures in the Pacific Ocean, it’s unlikely to make it into the top 5 in 2021.

NOAA also produces monthly temperature analyzes, which are usually published later than Copernicus’. The methods used by the two agencies are somewhat different – NOAA uses more observational data, Copernicus uses more modeling – but the results usually agree very well.