If you’ve lived in the Valley for a very long time, you might think these excessive heat warnings weren’t around when you were growing up.
You’re right. Sort of.
Paul Iniguez is a meteorologist with the National Weather Service in Phoenix. He says his agency has always had criteria that would prompt an excessive heat warning, but it was much more severe before.
"I believe it was a heat index of 125, not just apparent temperature, the heat index and that counts humidity and that has basically never been observed in Phoenix," Iniguez said. "So we had unrealistic criteria to start with."
Iniguez says when the Weather Service partnered with the state and county health departments, they realized heat is the biggest killer of any weather element in Phoenix.
There are 60 to 100 heat-related deaths each year, he says. So, in 2000, the agency started adjusting the criteria and made several changes over the years. Today, they use the forecast high and low temperatures to identify those excessively hot days.
