Why Indoor Air Feels Dry in Winter (Even in Southern California)

Dry indoor air during winter is a common issue in Southern California homes, especially when heating systems run more often. Even in a mild climate, heating can significantly reduce indoor humidity levels and affect comfort.

Why Indoor Air Becomes Dry in Winter

When air is heated, its relative humidity naturally decreases. This means that even if outdoor air is not extremely dry, running a heating system can make indoor air feel noticeably drier.

Many homeowners first notice this through dry skin, irritated sinuses, or static electricity. Some also experience scratchy throats in the morning or mild discomfort during the night, especially when the heater runs for extended periods.

This effect is more noticeable in winter because windows and doors remain closed longer, reducing natural air exchange.

How HVAC Systems Affect Indoor Humidity

Your HVAC system circulates and heats air throughout the home, and while it improves comfort, it can also lower moisture levels. Systems that run longer cycles can remove more humidity from indoor air, particularly if airflow or filtration issues are present.

Dirty air filters or restricted airflow can make indoor air quality feel worse because dust and particles circulate more easily. Reduced airflow can also make certain rooms feel less comfortable than others.

If you suspect airflow problems, this guide may help: How to Improve Airflow in Your HVAC System.

Signs Your Indoor Air Is Too Dry

Some signs of low humidity are easy to recognize. These include:

• Dry or irritated skin
• Static electricity when touching fabrics or metal objects
• Dry nasal passages or throat irritation
• Wood furniture or flooring drying or cracking
• Dust becoming more noticeable indoors

If you notice several of these symptoms, your indoor humidity level may be too low for comfort.

Simple Ways to Improve Indoor Air Comfort

There are several steps homeowners can take to improve indoor humidity and comfort during winter:

• Use a portable humidifier in bedrooms or living areas
• Replace HVAC filters regularly
• Keep interior doors open to improve air circulation
• Seal small air leaks around windows and doors

Even small improvements in airflow and humidity can make a noticeable difference in comfort.

When Dry Air Indicates a Larger HVAC Issue

In some cases, excessively dry air may indicate underlying HVAC issues such as duct leaks, airflow imbalances, or systems running longer than necessary due to calibration problems.

Routine maintenance helps ensure your system is operating efficiently and maintaining a comfortable indoor environment. You may also find this article helpful: Why HVAC Maintenance is Crucial: Avoid Costly Repairs and Keep Your System Running Smoothly.

When to Schedule an Inspection

If indoor air consistently feels dry or uncomfortable despite basic adjustments, a professional inspection can help identify airflow or humidity-related issues and recommend solutions tailored to your home.

Call (949) 229 6766 or schedule a service visit to improve comfort and indoor air quality in your home.