The summer of 2021 killed more than 100 people in Washington state during a single heat event that lasted less than a week. The temperature in Lytton, B.C. — just north of the border — hit 121°F. Sea-Tac recorded 108°F. Most of those who died were older adults, living alone, in homes with no air conditioning, in a region that had never needed it.

A Washington Post report this week on staying safe during extreme heat while traveling covers the basics well: hydration, timing outdoor activity, recognizing heat exhaustion. That's useful. But it's written for people in motion — tourists, road-trippers, commuters passing through a hot corridor. Washington households face a different problem. Most of the risk here isn't on the road. It's at home.

What's actually changing

Western Washington has historically skipped the air conditioning conversation. The assumption was that even hot summers topped out in the low 90s for a few days, then marine air rolled back in off the Puget Sound. That assumption is now unreliable.

The National Weather Service's Seattle office has documented a measurable shift in the frequency and intensity of heat events in the Cascade foothills, the Yakima Valley, and even coastal areas that once served as natural refuges. Eastern Washington — the Tri-Cities, Spokane, the Columbia Basin — already runs hot, but the window of dangerous temperatures is lengthening on both ends of the season.

The 2021 event was a "heat dome," a high-pressure system that stalled over the Pacific Northwest and reflected heat back down. Atmospheric scientists have said these patterns are becoming more common, though exactly how much more common is still being studied. What isn't contested: the infrastructure of much of Washington was not built for this, and hasn't been substantially updated since.

Roughly half of Western Washington homes still lack central air conditioning, according to state energy office surveys. Many older homes in Seattle, Tacoma, and Everett are poorly insulated, which means they trap heat rather than shed it. Mobile homes and apartments with west-facing windows are particularly exposed.

The travel-safety framing matters less than the at-home framing for most Washington families.

What we'd actually do

Map every person in your household and immediate network who lacks air conditioning. This is the single most important step. Knowing who is vulnerable before a heat event gives you options; finding out during one limits them. Make a short list: elderly neighbors, relatives in older apartments, anyone with a chronic illness that affects heat regulation. Text them now, not in July.

Heat-related death in Washington disproportionately hits people who are isolated. The 2021 data from the Washington State Department of Health confirmed that the majority of victims were found alone. A brief check-in call during a heat advisory — not a full welfare check, just contact — is genuinely protective.

Identify your county's designated cooling centers before you need them. King, Pierce, Snohomish, Spokane, and most other counties activate cooling center networks when temperatures exceed threshold levels, but those locations change year to year. The time to look this up is today, not on a 105°F afternoon when the website is slow and you're already overheated. Bookmark your county's emergency management page.

Washington's county emergency management sites are inconsistently updated. If you can't find cooling center information easily, call 211 — Washington's social services line operates statewide and maintains heat-resource referrals.

Buy a single window AC unit and decide where it goes. A single 5,000–8,000 BTU window unit costs $150–$250 at most hardware retailers and can cool one room adequately. That room becomes your household's refuge during a multi-day event. This is not a luxury purchase for Washington families anymore. Pick the room with the fewest west- and south-facing windows, ideally with a door that closes.

If you rent and can't install a window unit, a portable evaporative cooler ("swamp cooler") works acceptably in Western Washington's lower-humidity summers — less so in Eastern Washington's drier but also hotter conditions, where refrigerant-based cooling is more effective.

Keep a 72-hour water buffer that accounts for heat load. Standard emergency water guidance is one gallon per person per day. In extreme heat, that number should be closer to two gallons per person per day, accounting for drinking, minimal hygiene, and pets. If you have a family of four plus a dog, that's roughly 50 gallons for a long weekend event. Know where your nearest water source is if municipal supply is disrupted — heat events sometimes coincide with power failures that affect pumping stations.

Review your vehicle as a temporary shelter option, carefully. A car with functioning AC is a legitimate refuge during a short heat spike if your home becomes dangerously hot. It is also a death trap if left running in an enclosed space or if a child or pet is left inside unattended even briefly. Know your car's AC capacity, keep the gas tank above a quarter-full through summer, and park in shade whenever possible to reduce the cooling load.

Washington's preparedness culture tends toward earthquake readiness, and rightly so — the Cascadia Subduction Zone is real and the risk is not zero. But heat is a more frequent, more immediate, and in recent history more lethal threat for households in this state. The goal isn't to catastrophize summer. It's to not be caught without a plan when a heat dome stalls over the Cascades for the fourth time in five years.

Durability means your household can absorb a hard week without a crisis. For Western Washington families, a hard week increasingly looks like triple-digit heat, not a snowstorm.