Home Humidity Levels Chart. So you will need to adjust your humidity levels as the year goes on. Between 10F and 20F indoor humidity level should be less than 35.
To put this in perspective the Sahara Desert averages 23 humidity. Outside Air Temp C Maximum Indoor Relative Humidity at 20C 68F -30C or below 15. The chart below further illustrates what happens to air when its heated.
-30C to -24C 20.
By monitoring humidity you can ensure that you achieve the right humidity levels for your home inclusive of common humidity fluctuations and extraneous variables. This chart shows the relationship between relative humidity and various health problems -- especially as it relates to air borne pathogens. Outside Air Temp C Maximum Indoor Relative Humidity at 20C 68F -30C or below 15. Relative Humidity and Health.