How Winter Dryness is Affecting Your Indoor Air Quality

Updated: February 24, 2026

Since we’re smack dab in the middle of cold and flu season, it’s important to know how your home’s humidity can play a role in spreading sickness. During the winter months, the humidity in your home is generally very low because the warm air blowing from your furnace does not hold moisture as well as your A/C.

Ideally, you want to keep the humidity in your home between 40% and 60%. If the humidity level is below 30%, the air not only causes dry skin but it can also keep allergens and airborne pathogens from dying.

CleanAlert explains how viruses can travel through dry air:

In crystalline form, these infectious materials can spend several hours floating and recirculating through dry air (with relative humidity below 40 percent) and can travel a substantial distance depending on the air current. However, if the relative air humidity in the space is within optimal range of 40 to 60 percent, the salt concentration decreases to a level where most of the viruses cannot survive.

In addition to keeping bacteria and viruses alive, low humidity dries out your nasal passages and respiratory system. When nasal passages don’t have the natural moisture that mucus provides, your immune response is very weak and unable to fight off cold and flu viruses.

If you’re not sure what the humidity level in your home is, you can buy a hygrometer and test individual rooms. The best way to increase the humidity levels is to have a whole-house humidifier professionally installed into your existing ductwork. Portable humidifiers are another option, but then you have to move them from room-to-room and keep up with daily maintenance.

Richmond’s Air serves the greater Houston area, including Bellaire, Katy and Spring. Contact us today to talk about the best solutions for your home’s indoor air quality.

Continue reading: Health Benefits of Humidifiers & Dehumidifiers