Step 1. Measure the temperature of the air with the thermometer.

         Enter the air temperature: degrees (F)

Step 2. Fill a drinking glass 2/3's full with tap water. Add a few ice cubes and stir with the thermometer. Watch the outside of the glass as you stir. As soon as you see condensation (a haze) form on the outside of the glass, read the thermometer.

         Enter the water temperature: degrees (F)

The Relative Humidity is %

Condensation and Decay may occur on surfaces below degrees (F)

Mold and mildew may grow on any surface below about degrees (F)