The 2021 heat dome was a wake-up call for the Pacific Northwest. Temperatures hit 108°F in Seattle—a city where many homes didn't even have air conditioning. Since then, heat waves have become a regular summer feature.

Here's what we've learned about keeping homes cool when the heat gets extreme.

Before the Heat Wave Hits

Get Your AC Serviced Now

The worst time to discover your AC isn't working is when it's 100°F outside. Schedule a tune-up before summer heat arrives. We check refrigerant levels, clean coils, and make sure everything's running efficiently.

During a heat dome, HVAC companies are slammed with emergency calls. If you wait until the heat hits, you might wait days for service.

Change Your Filter

A dirty filter makes your AC work harder and reduces airflow. Replace it now, and check it again weekly during extreme heat. This simple step can improve cooling capacity by 5-15%.

Seal Air Leaks

Hot air sneaking in around windows and doors makes your AC work overtime. Check weatherstripping, apply caulk to gaps, and consider adding insulating window film to south-facing windows.

During the Heat Wave

Set Your Thermostat Strategically

During extreme heat, your AC may not be able to keep your home at 68°F—especially if it was sized for our typically mild climate. Here's what works:

  • Set it and leave it. Constant adjustments make your system work harder. Pick a temperature and stick with it.
  • Don't set it too low. Setting your thermostat to 65°F won't cool your house faster—it just runs the system non-stop and might freeze the coils.
  • Aim for 20-25°F cooler than outside. If it's 100°F out, keeping your home at 75-78°F is realistic for most systems.

💡 Pro Tip: Pre-Cool Your Home

If you know extreme heat is coming, pre-cool your home the night before when temperatures drop. It's easier (and cheaper) to maintain a cool temperature than to recover from a hot one.

Help Your AC Out

  • Close blinds and curtains on sun-facing windows. Solar heat gain through windows can add thousands of BTUs to your cooling load.
  • Don't use the oven. Cook outside, use a microwave, or eat cold meals.
  • Run heat-producing appliances at night. Dishwasher, dryer, and even your shower add heat and humidity.
  • Use ceiling fans. They don't cool the air, but moving air feels cooler on your skin, allowing you to set the thermostat a few degrees higher.
  • Turn off unnecessary lights. Incandescent bulbs especially—they're basically little heaters.

Create Cool Zones

If your AC is struggling to cool the whole house, focus on keeping key rooms comfortable:

  • Close doors to unused rooms
  • Close vents in rooms you're not using (but don't close more than 20%)
  • Concentrate your living in the coolest part of the house (usually lower floors)

⚠️ Watch for Signs of AC Struggling

If ice is forming on your AC unit, airflow has dropped significantly, or the system runs constantly without cycling off, call us. These are signs of problems that will get worse if ignored.

If You Don't Have AC

Many Pacific Northwest homes were built without air conditioning. If that's your situation:

  • Portable AC units can cool individual rooms effectively. Not as efficient as central air, but much better than nothing.
  • Window units are affordable and can make a bedroom comfortable for sleeping.
  • Consider a ductless mini-split for a permanent solution. They're efficient, don't require ductwork, and can be installed relatively quickly.
  • Create cross-ventilation at night when temperatures drop—open windows on opposite sides of the house and use fans to pull cool air through.
  • Know your cooling centers. During extreme heat, libraries, malls, and community centers provide air-conditioned refuge.

Protecting Vulnerable People

Extreme heat is dangerous, especially for:

  • Seniors and young children
  • People with chronic health conditions
  • Those taking certain medications
  • Pets (they can't sweat and overheat easily)

If you have family members in these groups, prioritize keeping at least one room reliably cool, and check on elderly neighbors who may not have adequate cooling.

After the Heat Wave

Once temperatures return to normal, take stock:

  • Did your AC struggle? It might be undersized or need service.
  • Were certain rooms unbearably hot? Consider ductwork improvements or supplemental cooling.
  • Did you wish you had AC for the first time? Now's the time to get quotes—before next summer's rush.

The Bottom Line

Heat domes are part of our new normal. Being prepared—with a well-maintained AC system and smart strategies for extreme heat—makes all the difference between uncomfortable and dangerous.

If your AC struggled during the last heat wave, or you want to add cooling to your home, don't wait until it's 100°F again. Give us a call now while there's time to plan properly.