The New York Times ran a story a day or so ago about the advances we've made in predicting heat waves. In a country where day-to-day high temps can range from the comfortable-yet-warm low 80s to the dangerously hot 110s, accurately predicting and preparing for heat waves is important for the public's health. Tack on the fact that global climate change is driving average temps in the summer ever-higher and you have a real reason to want to see these anomalies coming. 

From that article: 

From 1999 to 2010, about 620 people died each year, on average, from heat-related illness in the United States, according to the Centers for Disease Control and Prevention. Some heat waves have been especially lethal, like the one in Chicago in 1995 when more than 700 people, most of them old or infirm, died over five days.