Dew Point Calculator
Calculate dew point temperature and comfort level. Understand how humidity and temperature combine to create that 'muggy' feeling.
Use the slider for quick adjustments.
What is Dew Point?
The dew point is the temperature the air needs to be cooled to (at constant pressure) in order to achieve a relative humidity of 100%. At this point, the air cannot hold more water in the gas form.
If the air cools further, water vapor must condense into liquid water—this creates dew on grass, fog in the air, or condensation on a cold glass.
Dew Point vs. Relative Humidity
Relative Humidity (RH) tells you how close the air is to saturation at the current temperature. However, Dew Point is a better indicator of how "humid" it actually feels.
- High RH, Low Dew Point: A cold winter day might have 90% RH but a dew point of 30°F. It will feel dry to your skin.
- Low RH, High Dew Point: A hot desert day might have 30% RH but a dew point of 70°F. It will feel incredibly oppressive and sweaty.
Dew point is an absolute measure of the amount of moisture in the air. Generally, dew points above 65°F (18°C) feel uncomfortable to most people.
? Frequently Asked Questions
Relative humidity is relative to temperature. Dew point provides a fixed number that directly correlates to comfort. If the dew point is 70°F, it will feel muggy regardless of whether the air temp is 75°F or 95°F.
No. The dew point can never exceed the air temperature. If the air cools to the dew point, fog forms, and they drop together.
Most people find dew points between 50°F and 60°F to be very comfortable. Anything below 50°F feels dry and crisp.