Raining on Nov. 19…again? Seattle’s quirky ‘rain magnet’ date

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Published 7:23 am PST, Tuesday, November 19, 2019

SEATTLE — It’s raining outside Tuesday morning. Rain for today has been in the forecast for the past several days so it’s not a surprise.

But what if I told you that rain today could be predicted months — nay, years — in advance, and you’d be right a surprisingly number of times? Heck, my blog on Aug. 21 even correctly predicted it would rain today.

What’s the trick? No trick, just one of Seattle’s strange weather quirks.

Rain seems to gravitate to Nov. 19 like Seattleites to an REI sale. Over the past 125 years, Seattle has seen measurable rain on Nov. 19 a whopping 92 times.

(Looks out window) Oh, make that 93. That is a hair short of 75% frequency — or it rains on this date three years out of every four — like a backwards leap year. (That sentence got me wondering: Are the leap years the rare dry years? Does the rain destined for Nov. 19, rain on Nov. 20 that year? While 3 of this century’s leap years were dry years (2000, 2004, and 2008) there was no statistical correlation. THAT would have been an awesome coincidence.)

Click here for full-size image of a chart showing rain frequency in Seattle by date.

So Nov. 19 is the worst day for the picnic or outdoor wedding by a wide margin. Got it. (The next wettest days are Jan. 8 and 9 at 85 times over the past 125 years).

But apparently if that heart-of-the-stormy-season picnic must be around this time of year, just move it a day. As strange is the quirk that has Nov. 19 so frequently wet, the day before and after have been considerably drier. Nov. 18 had rain 69 times out of 125 years, and Nov. 20 also had 69 — and the forecast suggests the 20th will stay dry this year too. So…just move it a day?

Rain spike aside, the jet stream does like to call the Pacific Northwest home this time of year and November is statistically the rainiest month of the year (well, not this year, but most years). So it’s not surprising if we are going to have a day like this in our record books, it’d be in late November.

By the way, it’s not just Nov. 19 with the strange weather. There are plenty other quirks in Seattle’s rain records as well.

This article first appeared on KOMO NEWS.

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