Going a month and a half without rain was a big deal for Seattle, but for Portland—which saw its dry streak end Monday at 51 days—it didn’t mean as much.
Since it was only good enough for eighth place on the list of longest dry spells in the city.
When it comes to rain-free periods in the Northwest, there’s no question: Portland owns Seattle, and then some. Case in point: Portland’s longest stretch of days without measurable precipitation is 71—a whopping 20 days greater than our all-time record of 51. Second place on the Rose City’s list? 62 days—two weeks longer than our just-concluded 48-day drought.
In fact, Portland’s top seven dry streaks—ranging from 71 to 52 days—are all greater than our 51-day record. Why the disparity? It turns out that even though most of Portland is wetter than Seattle on an annual basis (downtown Portland averages five inches more rain a year than Sea-Tac), the city is drier in July and August. For instance, whereas Seattle receives 0.88 inches in a typical August, Portland sees only 0.65. While that’s not a massive difference, it’s enough that in years when Seattle sees very little rainfall in July and August, Portland stands a chance of seeing none.
Fall also tends to be drier in Portland than Seattle, as moisture-laden storms from the Pacific focus their energy north of the Columbia River. This year, however, both cities are likely to remain bone-dry well past the start of autumn, thanks to high pressure over the Northwest. All told, it wouldn’t be a surprise to see both Portland and Seattle rattle off 20-day dry streaks by month’s end.
In Seattle, that’ll generate quite the buzz. In Portland?
No biggie.
[…] thanks to a pattern shift of titanic proportions, Portland will have trouble breaking their amazing 71-day dry streak set in the summer of […]