A brutal heat dome blanketed the Pacific Northwest over the weekend, bringing life-threatening conditions to an area unprepared for extreme heat, with a third straight day of triple-digit temperatures forecast for Monday. On Saturday, the high temperature measured at Portland International Airport hit 108°F, breaking a record of 107° set in July 1965 for the hottest temperature there since records began in 1940. The new record was shattered a day later when highs reached 112°F. Seattle had its first-ever consecutive days with highs above 100°, reaching 102° on Saturday and 104° on Sunday, also an all-time record.

The region, known more for its temperate drizzle, is particularly unprepared for excessive high temperatures. Seattle ranks first and Portland third in the U.S. among cities with the highest proportion of households without air conditioning, according to the U.S. Census. Those least likely to have air conditioning are also most likely to be at risk from heat, including the poor, elderly, and historically underserved communities of color living in urban heat islands, agriculture and other outdoor laborers, and those with health conditions that make them particularly vulnerable when the temperature soars.

While several thousand people were without electricity Sunday, fears the power grid would not be able to handle demand have so far not come to pass. Heat waves kill more people on average in the U.S. than any other weather-related event, and are expected to continue to become increasingly frequent and severe with the effects of climate change. (Records: APAxiosWashington Post $, New York Times $, CBSFTReutersGizmodoMother Jones; Climate change link: The OregonianSeattle TimesBloombergAxios; Utilities and preparation: The OregonianCNNNew York Times $)