Cold Weather Climate and Condensation
Northern and Midwest regions of the U.S., or those places where the average January temperature is 35° F or colder, tends to have more occurrences of condensation. The greater the extremes between outdoor and indoor temperatures, the more likely moisture will become visible on your windows.
Bay, bow, and garden windows often create opportunities for condensation to show because air circulation is frequently limited, and their protrusion from the insulated house wall generally makes them a few degrees cooler. Heavy window treatments also limit airflow and increase the likelihood of condensation.
Acceptable Ranges of Temperature and Relative Humidity During Winter (in °F)
The humidity level that should be maintained in your home during the winter varies with the outside temperature. The colder it is outside, the lower the humidity level must be inside your home. All major manufactures of humidifiers list the recommended humidity settings based on outside temperatures. The following guideline is recommended by every major manufacturer of windows, doors, and humidifiers.
|Outside Temperature||Relative Humidity|
|-20° F||15% or less|
|-10° F||15% to 20%|
|0° F||20% to 25%|
|+10° F||25% to 30%|
|+20° F||30% to 35%|