WASHINGTON — Amid a scorching heat wave, the US National Weather Service (NWS) has issued heat alerts for 40 million Americans across at least a dozen states, from Montana to Texas and Florida.
Scorching temperatures will linger in the US Southwest while intensifying in the Midwest this week, Xinhua news agency quoted the NWS update issued on Monday as saying.
A heat dome that has been stationary over the Southwest is expected to stretch into the Midwest , it added.
Temperatures are forecast to reach or exceed 43.3 degrees Celsius in states including California and Arizona.
Arizona's capital city of Phoenix has now witnessed a record-breaking 24 consecutive days of temperatures above 43 degrees Celsius, well past the previous record of 18 days set in 1974.
Meanwhile, severe thunderstorms are forecasted for parts of Connecticut, Massachusetts, New York, Pennsylvania and Vermont.
Thunderstorms will continue to increase in coverage and intensity throughout the day as daytime heating destabilises the atmosphere, according to the NWS Storm Prediction Center.
The strongest storms will pose a risk of locally damaging wind gusts.
[bsa_pro_ad_space id=1]Meanwhile, at least 18 heat-related deaths have occurred in Arizona's Maricopa County since April, with 69 more fatalities under investigation.
The National Park Service has also reported at least four deaths among visitors.
Two female hikers were found dead in the Valley of Fire State Park in Nevada on Sunday, amid temperatures as high as 45 degrees.
The world has just sweltered through the hottest June in the 174-year global climate record.
The average global surface temperature in June was 1.05 degrees Celsius above average, ranking June 2023 as Earth's warmest June on record, according to the US National Oceanic and Atmospheric Administration (NOAA).
June 2023 was 0.13 of a degree warmer than the previous record set in June 2020.
June 2023 also marked the 47th consecutive June and the 532nd consecutive month with temperatures above the 20th century average, according to NOAA.
Additionally, Earth's ocean surface temperature anomaly -- which indicates how much warmer or cooler temperatures are from the long-term average -- were the highest ever recorded, according to scientists from NOAA's National Centers for Environmental Information.
Climate change and strong El Nino events are behind the unprecedented weather conditions, scientists said.