What is the dew point?

What is the dew point?

• A. The temperature at which air becomes saturated and dew forms.
• B. The temperature at which water boils.
• C. The temperature at which rainfall forms.
• D. The temperature at which humidity is zero.

Answer: (A)

Moisture in the air depends on temperature: warmer air can hold more water vapor than cooler air. The dew point is the temperature at which air becomes saturated with water vapor—when it can hold no more moisture at that pressure. At that point, water vapor starts to condense into liquid water, forming dew on surfaces. This isn’t about water boiling or rainfall forming, and it isn’t about humidity being zero; it’s about the temperature at which condensation begins given the air’s moisture. So, the dew point is the temperature at which air becomes saturated and dew forms.

Moisture in the air depends on temperature: warmer air can hold more water vapor than cooler air. The dew point is the temperature at which air becomes saturated with water vapor—when it can hold no more moisture at that pressure. At that point, water vapor starts to condense into liquid water, forming dew on surfaces. This isn’t about water boiling or rainfall forming, and it isn’t about humidity being zero; it’s about the temperature at which condensation begins given the air’s moisture. So, the dew point is the temperature at which air becomes saturated and dew forms.