Climatologically, this is the warmest week of Buffalo's year. The average daytime high is 80.2 degrees.
The heat that's coming later this week is extraordinary.
The mercury could soar more than 10 degrees beyond that by week's end, according to the National Weather Service. With expected high humidity, it could feel like it's in the triple-digits.
"We could definitely be looking at heat indices over 100 degrees or higher," said Jason Alumbaugh, a meteorologist at the National Weather Service.
Weather service forecasters said heat advisories are expected Thursday, Friday and Saturday. It's possible that excessive heat warnings could be posted due to "oppressively warm and humid" conditions.
The weather service criteria for posting excessive heat warning are when heat indices – the combination of temperature and humidity – meet or exceed 105 degrees for at least two hours.
Excessive heat warnings have only been required in Buffalo three times since 2005.
"It's very rare to have excessive heat warnings," Alumbaugh said. "That's when your body can really be zapped by the heat and humidity."
The heat can be dangerous, the weather service said.
Staying hydrated, avoiding strenuous activity and keeping track of the young and elderly is essential under those conditions.
The heat is being generated by a mid-level ridge that's been baking the Midwest. Tropical warmth and moisture will also arrive in Western New York as the remnants of Hurricane Barry track northward from Louisiana.
Those remnants are expected to arrive Wednesday.
"This will lead to showers and thunderstorms that will likely contain torrential downpours and locally heavy rain," the weather service said in its hazardous weather outlook. "This will elevate the threat for localized flooding."
That moisture will help to augment the low-level humidity when the heat arrives Thursday.
Dewpoints in the mid-70s are possible. That also means overnight temperatures won't likely drop below the low to mid-70s.
"Anytime you get a dewpoint over 70, it gets oppressive," Alumbaugh said.
So far this year, there has only been one 90-degree day when the temperature toe-touched 90 last Wednesday afternoon.
On average, Buffalo has three 90-degree days per year.