Dew Point Calculator

Dew point is one of the most reliable indicators of how humid the air feels. Unlike relative humidity, which varies with temperature, dew point remains constant for a given amount of moisture in the air. This makes it a superior metric for comparing comfort across different climates and seasons.

For example, a summer day in Phoenix at 105°F with 15% relative humidity has a dew point around 45°F — it feels dry. Meanwhile, a 90°F day in Houston with 60% humidity has a dew point near 74°F — it feels oppressive, even though the temperature is lower. Use our Heat Index Calculator to see how these factors combine.

Meteorologists use dew point to forecast fog, frost, and precipitation. When the overnight temperature is forecast to drop to the current dew point, fog or dew is likely. Pilots and aviation professionals also monitor dew point closely because it affects visibility and aircraft performance. See how humidity combines with temperature using our Heat Index Calculator.

Indoor dew points above 60°F (16°C) can promote mold growth, dust mites, and other allergens. The EPA recommends keeping indoor relative humidity between 30% and 50%, which typically corresponds to dew points between 40°F and 55°F (4–13°C) at normal room temperatures.

Low dew points (below 40°F / 4°C) can dry out mucous membranes, increasing susceptibility to colds and respiratory irritation. Using a humidifier in winter can help maintain a healthy balance. Monitor your indoor conditions with a hygrometer and adjust your HVAC or dehumidifier settings accordingly.