Ask Clay: What weather-casters mean by "normal weather"

Today’s question:

The TV weather people often refer to the normal temperatures. How do they determine what is normal?

This is kind of interesting.

On the one hand, “normal” is what you are used to. If you expect it to be hot and sticky in July and it is hot and sticky in July that is normal to you no matter how the temperatures or relative humidity might vary.

This, however, is somewhat lacking in precision. What you perceive as “normal” might be widely different from what your neighbor or your puppy dog consider it to be.

The National Weather Service determines normal temperatures by looking back at the last 30 years and averaging things out. That 30-year cycle is updated at the end of each decade.

If you would like to read a longer and much more complicated piece on what constitutes “normal” weather, poke around a bit at cimms.ou.edu. It might make your brain hurt, but it is pretty interesting.

I realize this does not affect us here, but how do baseball stadiums dry tarps after a rain delay? It doesn't seem they can just spread them back out on the field, and I doubt they have a clothesline big enough. Can you find out?

You are correct. This matter does not affect us here, but don’t you sometimes wish that it did? A good rain might make for a nice change and spice up the games a bit.

Of course they don’t hang the tarps on a huge clothes line or stuff them into gigantic dryers.

In stadiums that are open to nature the tarps are spread on the outfield to dry.