When a North Carolina heat wave settles in, many homeowners notice the same problem: the AC is running constantly, but the house still feels too warm. For families in Apex, Holly Springs and surrounding Wake County communities, this can be especially frustrating when outdoor temperatures stay in the 90s and humidity makes the air feel even heavier.
The National Weather Service’s 2026 Summer Climate Outlook for southeastern North Carolina notes that hotter summer temperatures increase the amount of energy needed for air conditioning. It also estimates that each 1-degree increase in average summer temperature can roughly equal a 6% increase in AC energy costs. That matters because extreme heat does not just make your home uncomfortable. It forces your HVAC system to work harder, longer and less efficiently.
In normal conditions, a properly sized AC system should help maintain a comfortable indoor temperature. But during a heat wave, several issues can prevent your system from keeping up. A dirty air filter, clogged coil, low refrigerant, weak capacitor, poor airflow or leaky ductwork can all reduce cooling performance. Even small problems become more noticeable when the system is under heavy demand.
Humidity is another major factor in North Carolina. Your AC does more than cool the air. It also removes moisture. If your home feels sticky even when the thermostat is near the set temperature, your system may not be dehumidifying properly. This can happen when airflow is restricted, the system is short cycling or the unit is not operating as efficiently as it should.
Before calling for service, homeowners can check a few simple things. Replace the air filter, make sure vents are open, keep blinds closed during the hottest part of the day and avoid setting the thermostat drastically lower than normal. Lowering the thermostat from 74 to 65 will not cool the house faster.
You should call HRD Air if the AC is blowing warm air, the indoor temperature keeps rising, rooms are cooling unevenly or the system never seems to shut off. A professional inspection can determine whether the issue is airflow, refrigerant, electrical components, ductwork or overall system age.
If your AC cannot keep up during a North Carolina heat wave, HRD Air can help homeowners in Apex, Holly Springs and nearby communities find the problem before it becomes a bigger summer breakdown.