evidence: One of, if not the, worst heat wave in the region’s modern records impacted the Pacific Northwest of the United States and western Canada during late June 2021, not just breaking records but smashing them over an incredibly hot four-day period. And unlike the heat wave across the Southwest United States in mid-June, this time the dangerous heat was felt across a region not known for such extremes. A week after a heatwave broke records across the Southwest and northern Mountain West, a second, even more anomalous, heatwave occurred across the Pacific Northwest and Western Canada. It sent records toppling. Over a four-day period, June 26-29, daytime high temperatures skyrocketed to well over 100 degrees Fahrenheit, setting all-time records at dozens of locations. [...] And finally, while there has not been an attribution study yet on this heat wave, climate change likely had an influence as well. As noted in the article on the previous record temperatures, heatwaves across the contiguous United States have occurred more often and lasted longer since the 1960s. According to NOAA’s Climate Extremes Index, the percent area of the Pacific Northwest that has experienced summertime extreme temperatures has drastically increased over the last twenty years. For the first 90 years of the record, an extreme heat footprint of larger than 50% of the area happened only three times. In the past 20 years, it has happened six times.