Dangerous temperature records are expected through the weekend on Southwest U.S. from California to Texas. More than 75 cities across the US could break daily records over the next few days. Arizona’s capital city reached 113 degrees on Friday, surpassing its previous record of 111 set in 1978. Las Vegas hit 109, breaking the previous record, set in 1996. Phoenix already is considered the hottest big city in the United States. Over 40 million people are affected. The temperatures forecast from Wednesday through Monday are the highest yet this year.The alerts cover portions of more than half a dozen states. AccuWeather forecasters and NWS stations across the Southwest have warned that temperatures will be 5 to 10 degrees above normal averages this weekend. The warning is set to remain in effect until Sunday evening. In Death Valley it’s expected to top 120 degrees for the first time this year. Nighttime temperatures can be dangerous in the same measure.
The effects of spiking temperatures are felt most acutely among vulnerable populations and workers outside. A person can lose up to 2 liters of fluid overnight through sweating if the temperature never drops below 85 degrees. Cramps, exhaustion, stroke and possibly death can occur. Excessive heat causes more deaths in the U.S. than other weather-related disasters. High pressure is to blame for the weekend heat wave, forecasters say. As the heat retreats from California, it begins to ramp up farther east. On Monday, most of the record temperatures will stretch between Denver and Raleigh, North Carolina, but could spread as far north as Wisconsin and Michigan. Thunderstorms over the next couple of days could cause flash flooding in areas that have been scorched by wildfire, forecasters said.