Seattle Weather Blog

Fall, Winter, Summer? Seattle Is Skipping Spring This Year

Yes, it really was that cold in April. And yes, it really is going to be that hot in May.

By Justin Shaw May 12, 2023

Editor's Note: Justin Shaw, author of Seattle Weather Blog, is now contributing to Seattle Met. This is his first story for the site.

Yes, it really was that cold.

And yes, it’s really going to be that hot.

In a remarkable display of weather whiplash, Seattle is heading into the weekend on the brink of a summer-like heatwave—just weeks after logging one of the coldest Aprils in recent memory. With potential 90-degree weather breathing down our necks, it may be hard to appreciate just how wickedly cold it was last month, so consider this bone-chilling fact: The first 25 days of April were Seattle’s third-coldest on record, topped only by 1955 and 2011 (barely). What’s more, only four of the 30 days in April managed an above-average high temperature—and all were courtesy of a late-month blast of heat that saw the mercury peak at 80 degrees on the 28th. In other words, on the rare April day Seattleites weren’t shivering, they were sweating. Really, spring—was that the best you could do?

Sadly, it appears so, because two weeks later, we’re about to leap straight into summer.

A mammoth ridge of high pressure is forecast to overtake the Pacific Northwest this weekend into early next week, potentially vaulting high temperatures into uncharted territory for mid-May. The projected location of this ridge of high pressure is strikingly similar to where the record-crushing heat dome of June 2021 set up shop—with its center located over southern British Columbia. This is highly unusual, as most heat domes of this magnitude are generally parked over the desert of the Southwest.

Fortunately, because it’s mid-May and not late June, Seattle will come nowhere close to the inferno that was late June 2021 (read: it’s not going to be 98 degrees, let alone 108 degrees!). That said, I think it’s a safe bet to say that many parts of the metro area will reach 90 degrees on Sunday, Monday, or both—and that includes parts of Seattle proper.

To be honest, reaching 90 degrees this early in the year in such a mild, maritime climate would be nothing short of ridiculous, not to mention unprecedented. Case in point: Seattle has only hit 90 degrees seven times in May in the postwar era—and never once before May 17. A reading of 90 or greater this Sunday or Monday would eclipse that mark, establishing a new record for the earliest 90-degree reading in city history.

It’s worth noting that there was a time when hitting 90 degrees in Seattle every year wasn’t a given—not even in July or August, let alone May. In fact, in five of the first 10 years of record-keeping at Sea-Tac Airport—from 1945 to 1954—Seattle never even reached 90 degrees. Heck, we even managed to dodge 90 as recently as 2011, a year which featured an even colder April than the one we just endured. This time around, however, it appears we’ll be lucky to make it past Mother’s Day without crossing into the 90s.

Is this an omen for what’s to come this summer?

And now, for the million-dollar question: Does this mean we’re due for another sweltering Seattle summer? Interestingly enough, a look back through history shows that the summers following 90-degree May days were generally average to a bit cooler than average. In other words, a hot May does not necessarily a scorching summer make.

On the other hand, in a warming climate, the value of looking far into the past for clues is probably diminishing—especially when we’re dealing with weather records from 50-plus years ago. If the past decade has taught me anything about Seattle weather, it’s that our summers are rapidly becoming warmer—regardless of whether there’s an El Nino, La Nina or some other large-scale weather phenomenon at play. Ultimately, the truth of how this summer might unfold probably lies in this jarring statistic: Eight of Seattle’s top-10 warmest summers have occurred since 2013.

So, get ready. This upcoming heatwave may very well be just the opening act in another blistering summer.

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