Welcome to Weather Insights. I’m your host, and today we tackle the question: Why do meteorologists prefer dew point over relative humidity? The dew point is “quite literally the point at which the air becomes dewy, wet, saturated.” Cold air holds less water vapor, so dew points stay low in winter. Warm air holds more, so summer dew points climb and it feels muggy. Relative humidity, by contrast, is “roughly equal to the dew point divided by the air temperature,” multiplied by 100. That means on a 90-degree day with a 70-degree dew point, the humidity is “only” 52 percent—but it sure doesn’t feel like it. When the air is moist, evaporation slows, and you can’t cool off after a shower or mowing the lawn. That’s why the heat index, or “feels-like” temperature, is so valuable. With a 70-degree dew point at 90 degrees, the heat index jumps to 96. Stay cool, stay informed, and thanks for listening to Weather Insights.
Link to Article