This is one of those things that’s worth thinking about earlier than most people expect. Writing this in May might feel a little premature, but by the time a real heat wave shows up in late July or August, it’s usually too late to react easily. Home improvement stores tend to sell out of fans, portable AC units, and anything cooling-related right when demand spikes. Getting ahead of it, even just mentally, tends to make the whole thing a lot easier.
Seattle isn’t traditionally thought of as a hot city, but when summer settles in, it can feel a lot warmer than people expect. A big part of that comes down to how the city was built. Most of Seattle’s housing stock was designed for long, damp winters, not sustained heat. Older homes in particular were built to retain warmth, and for decades that made sense. Average summer temperatures stayed mild, and hotter days were short-lived, so there wasn’t much reason to prioritize cooling.
That’s started to shift in recent years. Warmer, longer stretches of summer weather have made heat more noticeable, and the 2021 heat wave pushed that into focus for a lot of homeowners. Air conditioning, which used to be fairly uncommon in Seattle, has become much more prevalent, especially in newer construction and renovated homes. In older homes, it’s usually something that gets added later rather than something that was built in from the start.
The two most common cooling systems you’ll see are mini splits and ducted heat pumps, and they serve slightly different purposes depending on the home. Mini splits are ductless systems with wall-mounted units that cool specific rooms. They’re especially common in Seattle because many older homes don’t have ductwork, and installing a full central system can be disruptive and expensive. A mini split can be added to a main living space or bedroom and provide targeted cooling without reworking the entire house. Ducted heat pumps, on the other hand, use existing ductwork to cool the entire home and also provide heating. These are more common in homes that already have forced air systems or where someone is doing a larger renovation. In the Seattle area, heat pumps have also become more popular due to energy efficiency incentives and a broader shift away from traditional gas heating.
Even with more AC showing up, a large portion of homes still rely on simpler approaches. Fans are one of the main ones, but they’re not as integrated into homes here as they are in other parts of the country. Ceiling fans, for example, aren’t especially common in older Seattle homes, so most people rely on portable fans to move air through the house. That becomes especially important during the few weeks each year when nighttime temperatures stay elevated and homes don’t cool off as quickly.
The structure of the home itself plays a significant role in how it handles heat. Basements tend to stay cool, especially in older homes where they’re partially below grade and insulated by the surrounding earth. During hotter days, they’re often the most comfortable part of the house. Upper floors are usually the opposite. Heat rises and collects near the top of the home, and in houses with attics or limited ventilation, that heat can build up and linger into the evening. It’s common for bedrooms on the top floor to be noticeably warmer than the rest of the house, especially during extended warm periods.
Window placement and orientation also make a noticeable difference. West-facing windows, in particular, can bring in a significant amount of heat in the late afternoon and evening. Many Seattle homes, especially Craftsman-style houses, were designed to maximize natural light, which works well for most of the year but can lead to warmer interiors during the summer. Window coverings like blinds, shades, or curtains can help reduce that heat gain, and in some cases, exterior shading or landscaping plays a role as well.
Outdoor spaces reflect the climate in a different way. Lawns across Seattle typically turn brown in the summer, and that’s considered normal. Most homeowners don’t water heavily, partly due to cost and partly because it’s just not part of the local approach to landscaping. Grass goes dormant and comes back once the rain returns in the fall. Pools are also relatively rare. While they exist, they’re not a standard feature in Seattle homes. The number of consistently hot days is usually not high enough to justify the cost and maintenance for most people.
The hottest part of the year is generally late July through August. That’s when temperatures are most likely to reach into the 80s and 90s, and when heat can stick around for multiple days in a row. Earlier in the summer, especially in June, temperatures tend to be more moderate, and evenings often cool down quickly. Seattle’s long daylight hours during the summer also contribute to how homes heat up, with sunlight extending well into the evening and gradually warming interior spaces over the course of the day.
Because of all these factors, staying cool in Seattle tends to be less about a single solution and more about a combination of small adjustments. It’s common to open windows at night to bring in cooler air, then close them in the morning to keep that air inside. Fans are used to move air through the house, and people naturally gravitate toward lower levels or shaded areas during the hottest parts of the day. Over time, most people develop a feel for how their specific home responds to heat and adjust accordingly.
From a real estate perspective, cooling is becoming a more relevant consideration than it used to be. It’s not just whether a home has air conditioning, but how the home handles heat overall. Layout, insulation, airflow, and orientation all play a role, and they can make a meaningful difference once you’re living in the space, especially during the warmer stretches of the year.
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