Chicago and Detroit had the worst air-quality in the world on Tuesday as smoke from Canadian wildfires drifted across the upper Midwest.
Some residents in that area will remain under an air-quality advisory through Wednesday and as the storm moves east, air quality is expected to reach unhealthy levels in parts of western and central New York and eastern Lake Ontario, Gov. Kathy Hochul warned.
But for millions in Texas and the south-central US, dangerous heat remains the primary concern, and the evenings have offered little relief.
“There may be more danger than a typical heat event, due to the longevity of near-record or record high nighttime lows and elevated heat index readings,” the National Weather Service said.
And elsewhere in the U.S., we’ve seen the beginning of wildfire season.
Here’s a look at Wednesday’s forecast.
Texas brutal heatwave set to reach Central Plains and Mississippi Valley
Along with the dismal air quality in the upper Midwest, the main weather story across the nation Wednesday will be the intense, record-breaking heat wave that’s been scorching the south-central U.S. over the past couple of weeks, as temperatures are forecast to approach or surpass 100 degrees from New Mexico to Mississippi.
As of late Tuesday afternoon, more than 60 million Americans were under some level of heat alert from the National Weather Service.
The heat will be “life-threatening” to those working or spending time outdoors Wednesday, the weather service warned, due to the extremely high levels of humidity.
The heat index, which is how hot it feels with humidity factored in, will be in the 110-120 degree range across the eastern third of Texas, along the Central Gulf Coast and north through the Lower Mississippi Valley and Lower Tennessee Valley, the weather service said.
This includes the major metro areas of Dallas-Fort Worth, San Antonio, New Orleans, Little Rock, Jackson, Memphis, Montgomery and Nashville.
“Take this dangerous heat seriously,” said Weather.com meteorologist Jon Erdman. “Avoid any prolonged, unnecessary outdoor activity, especially in the hottest part of the day. Check on the elderly and anyone else who may be living without air conditioning.”
US heat index map
Heat, wildfires a concern in parts of California
After a relatively cool couple of weeks across much of California, summer has kicked off with an increasingly hot weather pattern for the interior Valleys of California set to start Thursday and continue into the weekend.
In Southern California, wildfire season appears to have commenced in Riverside County.
A brush flame, named the Juniper Fire, has spread 50 acres burning homes and leading to evacuations Tuesday afternoon in Perris, about 75 miles east of Los Angeles.
Southern California wildfire map
Canadian wildfires deteriorate air quality in Chicago
Poor air quality is set to continue in the Mid West, Great Lakes and Upper Mississippi Valley thanks to Canada wildfires, according to NWS. Detroit is under the NWS’s air quality advisory until Wednesday night.
Chicago and Detroit ranked as the two cities with the worst quality, according to IQAir’s Air Quality Index, switching back and forth between the “unhealthy” and “very unhealthy” categories through Tuesday.