Millions of Americans from Texas to Maine will be sweltering this week as a heat wave sweeps across the eastern US, forecasters say, with soaring temperatures set to hit the South starting Sunday before spreading across the Midwest and up the East Coast by midweek.
It's not officially summer yet, so baking season is still in full swing, but the early arrival of this muggy weather, and its forecast to continue for days on end, may come as a shock to many in the area.
Here are five numbers to help you understand the coming heatwave and our warming climate.
99
The high temperature expected in Pittsburgh on Wednesday is Fahrenheit, which would be the hottest temperature the city has ever recorded in June, said Josh Weiss, a meteorologist with the National Weather Service's Weather Prediction Center. (He noted that Pittsburgh has temperature records going back to 1875.)
The figure is just one of dozens of temperature records that Weiss said could be broken this week in cities across the northeastern U.S. About 20-day high temperature records are expected in the Ohio Valley on Monday, he said.
And daily and monthly high temperatures are expected to reach as high as 75 degrees Tuesday through Thursday as the heatwave moves from the Mid-Atlantic coast to New England, with many of those areas expected to reach over 95 degrees by midweek.
22.6 million
The number of people across the U.S. under heat watches, watches or warnings on Saturday was roughly equal to the population of Florida, according to the National Weather Service.
Experts say that while the numbers don't cover everyone affected by the heatwave, they do show the vastness of its impact — in other words, even if you don't live in an area with a heat wave warning, it's still worth taking precautions.
The heat wave “will impact heavily populated areas that haven't seen much heat recently,” said Daniel Swain, a meteorologist at the University of California, Los Angeles. “Now it's New England's turn.”
12
The number of consecutive months when the global average temperature has been the highest on record. Last month was the hottest May on record. In June, that number could reach 13.
“It's fair to say at this point that climate change is intensifying impending heat waves,” Dr Swain said.
1,220
According to the Centers for Disease Control and Prevention, extreme heat is the deadliest weather event of all. (By contrast, flooding kills about 98 people a year.) But that figure is likely an underestimate, because heatstroke deaths are hard to track, since extreme heat can worsen underlying health conditions. It also tends to be most dangerous for people who are already vulnerable to heatstroke, such as older people without air conditioning.
Scientists and health experts say they hope treating the heatwaves like other natural disasters will encourage people to take more precautions.
Four
The highs are the new scale the National Weather Service and CDC have created to measure the health risks associated with extreme heat in a given location on a given day. As anyone who's spent summer days in Houston or Phoenix can tell you, not all heat feels the same, and experts say even slightly cooler temperatures and higher humidity can make things even more dangerous.
The measure, called “heat risk,” is based on CDC data and takes into account how unusually hot the heat is for that time of year, the duration of the heat wave, and whether the temperatures pose a high risk for an area.
Monday's forecast puts parts of central Iowa, western Illinois and Missouri (including Kansas City) at the highest risk level of 4, which puts all residents at risk, is likely to significantly increase emergency room visits and could be deadly for the most vulnerable. Cities such as Chicago, Cleveland and Buffalo are at higher risk as the heat wave spreads.
Meteorologist Weiss said the new tool will help people understand that the risk of heatstroke can be exacerbated by a variety of factors.
For example, this week's heat wave could continue into next weekend in parts of the Northeast, where residents are unaccustomed to and unprepared for temperatures in the high 90s, especially in mid-June, and forecasters predict the heat will continue and may not offer any respite at night, creating a much higher risk of health problems.
“Without mitigation, heat stress will build up during this heat wave,” Weiss said.
Austin Gaffney Contributed report.