Much of the Great Lakes and Ohio Valley is now sizzling under a potentially record-breaking heat dome. The intense heat will spread eastward into the Northeast and New England on Thursday, and southward into the Mid-Atlantic by the weekend. Heat alerts are in effect across 14 states in the affected regions as officials warn people, especially those without access to air conditioning, to take precautions against heat illness.
Temperatures will soar into the mid-90s to near 100 in many locations, while heat indexes — a measure that also factors in the humidity — will rise to near 100 to 105. The heat won’t necessarily be historic, but many calendar-day records are likely and some monthly records are possible.
The fact that the heat is occurring so early in the season and persisting over multiple days “will increase the danger of this heat beyond what the exact temperature values would suggest,” the National Weather Service said.
Advertisem*nt
Many locations are predicted to reach the highest levels of the National Weather Service’s HeatRisk forecast, which rates the danger to human health. Officials are urging people to stay hydrated, wear light clothing and take breaks in the shade or indoors if they must be out in the heat for an extended period.
Indianapolis, Detroit, Cleveland, Cincinnati, Buffalo, Pittsburgh, Philadelphia, D.C. and Baltimore were all predicted to reach a Level 4 HeatRisk at some point during the heat wave. That is the highest level, described as “rare and/or long-duration extreme heat with little to no overnight relief.” Many other cites were forecast to reach Level 3, a level of heat that “affects anyone without effective cooling and/or adequate hydration.”
The heat is surging into northern portions of the Northeast that rarely see prolonged periods of such extreme temperatures in June. The heat index hit 101 in Buffalo on Tuesday and is forecast to reach the mid- to upper 90s on Wednesday and Thursday. In Rochester, N.Y., the heat index soared to 103 on Tuesday and could climb as high as 104 on Wednesday.
Advertisem*nt
Of the affected cities, Pittsburgh may endure the longest duration of intense heat, rivaling a record-setting stretch in 1994. Syracuse, N.Y., could set a record for its longest stretch of days reaching 94 degrees or higher in June.
The high-pressure heat dome responsible for the dangerous heat could reach a record level of intensity in parts of the United States. Research shows that human-caused climate change is enhancing the strength, size and frequency of such events.
Here’s a city-by-city forecast for the heat this week into the weekend.
Albany, N.Y.
After reaching 94 on Tuesday, short of the calendar-day record of 97, near-record highs in the mid- to upper 90s are expected Wednesday and Thursday. The calendar-day records are 94 on Wednesday and 97 on Thursday. The heat index should reach near 100 to 105 each day. Highs should be closer to 90 Friday and this weekend, and then in the 80s to near 90 next week.
Boston
The heat peaks Wednesday and Thursday with highs in the mid- to upper 90s, potentially close to the calendar-day records of 96 on Wednesday and 98 on Thursday, with the heat index peaking near or past 100 both days. Cooler highs in 80s are expected Friday through much of next week, and highs may be in the 70s on Saturday.
Chicago
After highs reached the mid- to upper 90s Sunday through Tuesday, they should reach the mid-90s Wednesday, with the heat index peaking in the upper 90s. Somewhat cooler highs in the upper 80s to mid-90s are expected Thursday through much of next week. Calendar-day record highs for the period are in the upper 90s to low 100s.
Cincinnati
Highs are forecast in the mid- to upper 90s through Sunday, with the heat index reaching 100 to 105. Calendar-day record highs range from 97 to 99 through the period. “Overnight lows will only drop into the 70s, providing little to no relief,” the Weather Service said. Somewhat cooler highs in the upper 80s to mid-90 are expected Monday through much of next week.
Cleveland
Highs should reach near 90 to the low 90s through Sunday, with the heat index reaching the mid- to upper 90s each day. Calendar-day record highs range from 92 to 96 through the period. Next week, more seasonable highs in the 80s to near 90 are expected.
Detroit
Highs are forecast in the low to mid-90s through Saturday, with the heat index peaking near 95 to 100 each day. Calendar-day record highs range from 95 to 99 through the period. Cooler highs in the 80s should arrive by Sunday and continue through much of next week.
New York
The heat starts to build with highs near 90 on Wednesday and the heat index reaching the mid-90s. Highs will increase to the low to mid-90s Thursday and Friday, and may fall short of the calendar-day record highs of 98 on Thursday and 97 on Friday. The heat index should reach the upper 90s both days. Highs should cool a bit to the upper 80s to near 90 Saturday into next week. If temperatures reach 90 degrees on six consecutive days, it would be the first time they would have done so in the city during June.
Philadelphia
The heat builds Wednesday and Thursday with highs in the low to mid-90s. More intense heat is forecast for Friday through Sunday, with daytime highs in the mid-90s to near 100 and the heat index peaking near 100 to 105 each day. Calendar-day record highs range from 97 to 100 through the period. Highs should be closer to 90 or the low 90s Monday through much of next week.
Pittsburgh
Highs should reach the mid-90s to near 100 through Saturday, while the heat index should peak near 100 to 105. Calendar-day record highs range from 95 to 98 through the period. Highs cool to the 80s to near 90 on Sunday and through much of next week. The last time the city experienced heat of similar intensity and duration was 30 years ago, when daytime highs reached 95 or higher for six straight days, June 15-20, 1994, the longest such stretch on record, according to the Weather Service.
St. Louis
After reaching highs of 97 and 96 on Sunday and Monday, Tuesday cooled off to highs in the upper 80s. Wednesday should trend warmer again with low 90s for highs, before heating up to the mid-90s to near 100 Thursday through Saturday. Calendar-day record highs range from 99 to 105 through the period. Highs could remain in the mid- to upper 90s through much of next week.
D.C.
The worst of the heat is expected Friday through Sunday, with highs in the mid-90s to near 100 and the heat index reaching near 100 to 105. Calendar-day record highs range from 98 to 101 through the period. The city has a chance to reach 100 for the first time since 2016. Overnight lows in the 70s will offer little relief.
Matthew Cappucci and Jason Samenow contributed to this report.
