Heat Wave #2

     We are headed for Heat Wave #2 this summer and there will likely be another heat wave in August.  There are lots of hot days during a Kansas City summer but how do we define a heat wave?  Some experts say it is when the morning low temperature stays above 75 degrees.  Several studies show an increase in heat related illness and deaths when it doesn’t cool off enough at night.

     The National Weather Service says a “heat wave” is a period of abnormally and uncomfortably hot and unusually humid weather.  But what’s hot and humid to us might not be that hot and humid to others, so the NWS definition is a bit muddy.

   Here in the 41 Action News Weather Center, our definition of a heat wave requires three or more consecutive days with high temperatures at or above 95 degrees.  We have lots of days in July and August when the afternoon high is 90 degrees but only once or twice a summer will we experience an extended stretch of hot weather with highs at or above 95 degrees. 

  So while there is some debate as to what constitutes a heat wave, there is no debate that hot weather is life threatening.  41 Action News Meteorologist Jeff Penner says heat often kills more people every year than hurricanes, tornadoes, lightning or floods. 

  Why is heat so potentially deadly?  Because heat often comes with humidity and humidity often makes the heat’s effect on the body worse.  We report the combination of heat and humidity as the heat index.  Studies show when the heat index climbs above 105 for three or more hours during a summer afternoon the number of people suffering heat illness also climbs.

   What can you do to fight the heat?  Most importantly take the heat watches or heat warnings seriously.  This weekend a heat advisory or excessive heat warning will be issued.  That means starting Saturday and lasting through much of next week there will be:

• Consecutive days with a Heat Index of at least 105 F for three or more hours per day.
• Consecutive days with nighttime lows above 80 degrees.
• Any period of time with a Heat Index above 115 F.

At the beginning of this blog post, I said there would likely be another heat wave in August.  Most years our hottest weather of the summer occurs during the first two weeks August.  The way things are going the August heat wave is shaping up to be hottest of the Summer!  Ouch!