Weather or Not: Heat and Humidity

Have you ever wondered whether or not humid air is more dense than dry air? How fast a car can heat up in the summertime? Here's what you need to know about heat and humidity!

Weather or Not: Heat and Humidity

Summer months are quickly approaching. Heat and humidity can be a dangerous combination on humans and your pets.

You often hear people say it is harder to breathe when it is more humid. 

What we are really talking about is the density of the air. 

Is humid air more dense than dry and cold air? Believe it or not, humid air is less dense than dry air. The atmosphere is made up of 78% nitrogen and 21% oxygen. Water vapor is fairly light compared to oxygen and nitrogen in the air. If there is more water vapor, it replaces some of the nitrogen and oxygen and the air becomes less dense.  Relative humidity greater than 50% can make it feel like the air is heavier, but it isn’t. It just feels that way because your body is trying to stay cool. Hot and humid air can cause problems for those with asthma. 



Sometimes on very dry days, air sinks and you can get higher pollution levels which can make breathing difficult.

Higher temperatures and high humidity can result in health risks. On average, we'll see 130 heat deaths in a given year in the United States according to NOAA. When you combine the actual air temperature (in the shade) and the humidity levels, you can get a “feels like” number or “heat index”.

When temperatures are above 80 degrees, dehydration can occur. At 90 degrees or higher, heat cramps occur. By the time you hit heat index values at or over 105, you are in dangerous territory as heat exhaustion sets in. By 130 degrees, you can get heat stroke and that can result in death. 

We always remind people to check the backseat during the summer months. Cars are heat traps and every year we see child vehicular heatstroke deaths. As of mid-May 2017, we have already seen six deaths and average over 30 per year since 1998.

Staying in a hot car just one minute can lead to sweating and difficulty breathing. Let's say it is 80 degrees outside and you stay in a car for 10 minutes. It feels like it is 100 in the car. 90 degrees outside? It feels like it is 110 degrees in the car in just ten minutes. Already risking the chance for heat exhaustion in a short period of time. 

What about 30 minutes? In just 30 minutes, it can feel like it is over 120 degrees if the outside air temperature is 90. The inside temp can reach 105 degrees if the outside temperature is a cool 70. 

   

By an hour, a car could feel as hot as a 140 degrees if the outside temperature is 95 degrees. At that point, you are well beyond the point of heat stroke. Which is obviously deadly. 


Be responsible. Check the backseat. Stay hydrated and don't forget about your furry friends too. 

 

 

© 2017 WMAZ-TV


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