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There is a running philosophy that we’ve come up with when it comes to dressing properly for the weather. We all know there are some major things that need to be avoided no matter what the season. Not only can cold temperatures lead to frostbite, hypothermia, and potentially death, but it’s actually the heat that is the number one weather related killer in the United States on a yearly basis. The combination of heat and humidity is dangerous, which is why we focus on dew points when forecasting in the summer months. With running so popular these days, it is important to be prepared with a good weather forecast so things like Chicago don’t happen again.

Let’s go through what we think you should wear at certain temperatures. Remember, there are different variations and different people react differently to certain weather so we keep that in mind. Temperatures are in Fahrenheit.

Anything below 35 Degrees – A long sleeve shirt and tights should be worn.

35-42 degrees – Shorts CAN be worn if racing, otherwise a long sleeve and tights. Most people will race in the latter.

43 Degrees and Above – Shorts and a t-shirt in most situations. The exception is a strong wind with highs in the lower 40s.

Things to Consider

If you are racing you may want to wear less, particularly on your legs. If there is full sunshine, it will more than likely feel warmer, so you may want to wear less at the lower temperatures. If it’s cloudy it will feel a little cooler at lower temperatures, so you may want to add a layer If it is windy you may want to wear more, as wind chills will make it feel even colder to exposed skin. Then of course there is the rain. If it is raining be sure to have the proper gear for the start and finish of the race. You can still race in shorts and a t-shirt with temps in the 40s and rain but you’ll need the warm clothes and a towel at the end of the race, trust me, spoken from idiotic experience!

Heat and Humidity (Dew Points)

People are always writing in to ABC 7 in D.C. asking why we always show the dew points in the summer. They always want to know the humidity percent. Think about this for a minute… Relative humidity is calculated with the temperature and the dew point in a series of equations that are actually quite complex. If it is 40 degrees with a dew point of 30, relative humidity is 67%. Though if it’s 85 degrees with a dew point of 65, relative humidity stands at a measly 51%. I’m guessing you can tell me which is more dangerous. That same temperature combination was at the 2007 Chicago Marathon which was cancelled mid-race. Here is the heat index chart you should consult during the summer months. Don’t worry, I will let you know the forecast heat index in each race forecast.

 Dew Points

55-60 – Sticky

60-65 – Uncomfortable

65-70 – Excessively Humid

70+ – Unbearable

Heat Index Chart

You should use caution when running in the summer months. Be sure to hydrate adequately and plan your runs in the early morning hours during the coolest part of the day. Running in the peak heating hours can be dangerous to your health.

Wind Chill Chart

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