NORFOLK, Va. — The old saying goes “it’s not the heat, it’s the humidity!” And while that may be true, it’s only half of the story. It’s the “dew point” that really matters. But what is the dew point?

It’s that time of year when the lexicon of the meteorologist regularly includes the phrase dew point. This concept is often confused with relative humidity which doesn’t tell us anything about how you ...