September 4, 2024<\/p>\n
4 min read<\/p>\n<\/div>\n
Brutal Heat Wave Will Extend Streak of 100 Days of 100 Degrees F<\/p>\n
Summer has been brutally hot in the Southwest, toppling records set just last year, and the heat isn\u2019t over yet<\/p>\n<\/div>\n
By Andrea Thompson<\/a><\/p>\n The NWS HeatRisk map for the Western United States on September 5, 2024.<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/div>\n For the past 100 days in Phoenix, Ariz., the temperature has risen to\u2014and often well above\u2014100 degrees Fahrenheit (37.8 degrees Celsius). In this city and much of the heat-weary Southwest, that streak will last at least a few more days as yet another heat dome<\/a> settles over the area and sends temperatures soaring.<\/p>\n The heat wave punctuates what has been a record-hot summer for parts of the Southwest, including the major cities of Phoenix and Las Vegas\u2013one that has toppled the previous records for the hottest meteorological summer<\/a> set in those cities just last year. \u201cIt\u2019s kind of rare to see that happen two years in a row,\u201d says Matt Salerno, a meteorologist at the National Weather Service\u2019s (NWS\u2019s) Phoenix office. \u201cThat\u2019s quite the feat.\u201d It\u2019s even more startling that the city broke its record from last year by nearly two degrees F (one degree C), with an average temperature of 98.9 degrees F (37.2 degrees C). \u201cThat\u2019s incredible, just to think of the average temperature that we\u2019re living in here in Phoenix,\u201d Salerno says.<\/p>\n Las Vegas has also set records by \u201cjust about any metric you look at,\u201d says Matt Woods, a meteorologist at the NWS\u2019s Las Vegas office. \u201cIt\u2019s been brutal.\u201d<\/p>\n If you’re enjoying this article, consider supporting our award-winning journalism by subscribing<\/a>. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.<\/p>\n In both cities, the tenor of the heat<\/a> has been a little different this summer compared with that of last summer. The Southwest started off with a mild June last year, followed by a July that was off the charts, and then things cooled down again late in August when Hurricane Hilary stormed through<\/a>. This summer hasn\u2019t reached the same peaks as July 2023, but it has been steadily scorching from the jump. In Las Vegas, \u201cwe only had six days this summer that had a high temperature below 100 [degrees F],\u201d Woods says. Meanwhile Phoenix\u2019s streak of 100-degree-F days has completely blown past the city\u2019s previous record of 76 such consecutive days, which was set in 1993.<\/p>\n The record-breaking heat of both summers has come from a series of heat waves where masses of hot air that park over an area for days. \u201cWe\u2019ve basically had that for the overwhelming majority of the summer,\u201d Woods says. The clear skies that accompany these features mean \u201cland surfaces heat up day after day,\u201d which in turn heats up the air just above the surface, Salerno says. Such heat waves are happening more frequently<\/a>, lasting longer and becoming more intense because of the excess heat trapped by greenhouse gases that have been generated by burning fossil fuels.<\/p>\n This week\u2019s heat wave won\u2019t be as intense as the one that suffocated the region in July, and it won\u2019t last as long, \u201cbut it\u2019s definitely unusual for this time of year,\u201d Woods says. It is extending the amount of time residents are being subjected to conditions that bring a serious risk of illness. \u201cJust because the temperatures aren\u2019t what we saw in July doesn\u2019t meant they aren\u2019t dangerous,\u201d Woods says. In the U.S., extreme heat is deadlier than hurricanes, floods and tornadoes<\/a> combined.<\/p>\n Those at particular risk of heat exhaustion, heat stroke and other heat-related health problems<\/a> include very young children, older people, those who have certain existing health conditions or are on particular medications<\/a>, people who work outside<\/a> and unhoused individuals. Both Woods and Salerno emphasize the need for all people in any heat wave to stay hydrated<\/a>, avoid going outside during the peak heat of the day, and seek out shade or air-conditioning<\/a> when at all possible. Both scientists also warn that people should never leave a child or pet unattended in a car; so far this year, 27 children have died of heat stroke after being left in a vehicle.<\/p>\n \u201cEssentially all heat-related deaths are preventable,\u201d says Kristie Ebi, an epidemiologist who specializes in heat-related health risks. Many cities, including Phoenix, are looking for ways to better warn residents and to reduce deaths and hospitalizations from heat-related illness. The NWS has also been working on better warning practices, including a new experimental tool called HeatRisk that shows locations where heat will be extreme<\/a> enough to represent a serious health concern.<\/p>\n![\"The](\"https:\/\/static.scientificamerican.com\/dam\/m\/41e2d4bd55460d2d\/original\/heat_risk_map_september_5_2024.jpg?w=600\")
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