Ask almost any person who doesn't live in Seattle about our weather and you're almost always going to hear the word “rain”. In reality, we don't get a lot of heavy rain but have many days where there's at least some. This past week, however, was very different, as we had a historic heatwave.
We've had heatwaves before where we've topped 100°F, but not more than a single day. We've also had times where we've been in the 90s for a few days, but it cooled off. Even during the heat waves, there's usually only one or two nights where it's really warm; normally there's a nighttime respite.
The recent heatwave was unlike any other the city has seen. Here's five days' worth of temperatures on our back porch:
While it's like other heat waves in that we cooled off pretty quickly after it's done, we had more hot days in a row than we're used to. The dark blue lines are the actual temperatures, while the grey lines take humidity into account. Highs and lows for actual temperatures are:
| 6/24 | 6/25 | 6/26 | 6/27 | 6/28 | 6/29 | 6/30 | 7/1 | |
|---|---|---|---|---|---|---|---|---|
| Low | 59.0 | 63.1 | 66.9 | 72.5 | 75.2 | 68.4 | 63.9 | 64.9 |
| High | 84.2 | 87.3 | 100.2 | 102.0 | 107.2 | 90.3 | 80.8 | 77.5 |
As you can see, the highs ramped up very quickly, then came down just as quickly, while the lows didn't swing quite as much.
We don't have air conditioning, so the inside also got warm. Temperatures on our main floor:
| 6/24 | 6/25 | 6/26 | 6/27 | 6/28 | 6/29 | 6/30 | 7/1 | |
|---|---|---|---|---|---|---|---|---|
| Low | 70.5 | 72.9 | 75.9 | 80.8 | 83.1 | 79.9 | 76.5 | 74.3 |
| High | 79.9 | 82.4 | 87.6 | 90.7 | 93.6 | 89.2 | 82.0 | 77.4 |
As you can see, we were mostly able to keep the house livable, and the two nights in the 80s were the only ones that the heat made it harder to fall asleep.
Temperatures on the second floor were quite a bit warmer; I don't have historic data, but we did see about 100°. I checked the basement on 6/27 and saw about 73°, so we spent quite a bit of the 28th down there.
For extreme heat, we are aggressive about window and window covering management. First thing in the morning, windows get opened and coverings opened to allow air in, except on the east side of the house to control sunlight coming in. Once the outside temperature goes above the inside, windows get closed (except for skylights) and curtains on the east get closed. When the outside temperature goes below the inside, we open the windows again until we go to bed.
The effect of window management is most evident on the graph for 6/29 (the markings are a bit skewed, so don't line up exactly with midnight). The sharp drop is when we opened the windows in the morning, and in the evening you can see the temperature drop more sharply when we opened the windows in the evening, then go back up when they were closed.
