A prolonged and potentially dangerous heat wave will scorch large stretches of the U.S. starting this week, with record-breaking temperatures expected to persist through the 4th of July holiday, forecasters said.
The National Weather Service warned that heat index values are likely to exceed 100°F. “Dozens of record highs are expected later this week across much of the Northeast,” the NWS said.
The risk of fire danger has also been elevated in Utah, Colorado, Arizona, New Mexico, Wyoming, Nebraska and South Dakota.
At the same time, an unusually cool weather pattern is keeping temperatures below normal in much of the western U.S., with some higher-elevation areas of Montana’s northern Rockies receiving significant snowfall.
Heat advisories
A map of the continental U.S. showing daytime high temperatures forecast for Wednesday, July 1.
(National Weather Service)
More than 175 million Americans are under some sort of heat advisory, watch or warning as of Monday afternoon. Much of the central and eastern U.S. will experience temperatures in the 90s and lower 100s this week. The high humidity levels will cause heat indexes between 105°F to 115°F across portions of the southern Plains, Mid-Mississippi Valley and eventually into parts of the Mid-Atlantic, forecasters say.
“The combination of prolonged daytime heating and limited nighttime relief will increase the risk of heat-related illnesses, especially for vulnerable populations and those without adequate cooling,” the Weather Prediction Service said in a Monday update.
Forecasters advise the following precautionary actions to stay safe in extreme heat: drink plenty of fluids, stay in air-conditioning and out of the sun, never leave children or pets in unattended cars and check on relatives and neighbors.
Over 3.7 million Americans are also under red flag warnings as the risk of fire danger has been elevated in portions of Utah, Colorado, Arizona, New Mexico, Wyoming, Nebraska and South Dakota.
Winter weather in June
Unseasonable cold and mountain snow are currently affecting the western U.S.
“Persistent troughing over the Pacific Northwest will continue bringing below normal temperatures across much of western U.S.,” according to a Monday update from the NWS.
In the northwestern U.S., parts of the northern Rockies have seen some serious powder. Darkhorse Lake in Jackson, Mont., which is nearly 6,500 feet above sea level, received 21 inches of snow that started early Sunday morning. Over 1,000 people in the Absaroka-Beartooth Wilderness of southern Montana are under a winter weather advisory through Monday evening.
Williams Creek Summit near Cobalt, Idaho, received 8 inches of snow as of Sunday evening.
