Weather Blog

Take a peek into some of Seattle's oldest weather journals

Take a peek into some of Seattle's oldest weather journals

We've all heard the "back in my day, we walked to school in the snow, barefoot, uphill (both ways!)" from our elders, but we've found some data that goes back to likely when your grandfather wasn't even a gleam in the eye.

UW Research Meteorologist Mark Albright was poking around the National Climatic Data Center archives and came across some very old weather journals for the Seattle area. How old? Before the Dennys and Mercers even landed at Alki!

Take a look at this weather log from Fort Steilacoom (just south of Tacoma) -- it's dated November 1849! (The earliest one he could find.)

You can see the full resolution here.

It provides an excellent window into how weather records were kept way back when.

The first columns are temperature observations. It looks like someone was in charge of taking a reading at sunrise, 9 a.m., 3 p.m., and again at 9 p.m. Note that this likely doesn't very accurately track the high and low temperatures since those are typically around 5 a.m. and 5 p.m. (give or take), but for what they had to work with, this is pretty impressive.

The next column is is a tracking of sky cover, "Clearness of the sky". At first, I thought this was percent sky cover in tenths -- today, a '0' means complete sun and a '10' means complete overcast.

But I think judging that this was November, there are way too many zeros for this to be sky "cover" and I'm betting it's the reverse -- percent (in tenths) of how much the sky was *clear* -- that would mean a '0' is overcast and 10 would be clear.

Next over is the wind. Since anemometers were not widespread (the current model we use today was invented in 1846 in Ireland -- just three years ahead of this journal, and it's not like they had FedEx then), I think this is the infant use of something along the lines of the "Beaufort Scale" where you assign a number based on wind intensity.

(0 is calm, 2 is "gentle breeze", etc.) It's hard to read the writing, but I think that's a direction in front, so an entry of "N2" would be a gentle breeze out of the north.

Over again is the "Clouds" column.

This one is a tough one for me. These might be codes to denote a type of cloud and which way they are moving (based on that Beaufort Scale) but some of the entries in the wind column look the same as the clouds column, making me think it's a direction and speed of cloud movement.

(I was thinking perhaps cloud type because Canadian observers to this day report type of cloud in their weather observations.)

Finally, we get to the rain column. I believe the first two columns are saying when the rain started and stopped, and the third column is the rain amount in tenths or twentieths of an inch.

I think some entries are "Cont." which I'm guessing means it was continuous. If so, it looks like it rained pretty much non stop from Nov. 15-26 that year.

The numbers are all totaled at the bottom. If I can read the number right for rain, it looks like it rained 9 and "2 tenths" and "1 twentieth" -- or 9.25".

Other neat notes:

* Thanksgiving wasn't nationally recognized yet, but it rained over what would have been the entire Thanksgiving weekend anyway, proving Puget Sound's weather traditions have some deep history behind them.

* Look up at the top: It says Steilacoom, Puget Sound, Oregon. Yes, this was back before Washington was a state and this was part of the Oregon Territories.

Here is one from 1870:

Here is a chart for Lake Washington observation for July 1870. This helps better understand the cloud observations -- here they are charting type of cloud ("Cir" is Cirrus and "Cu" is cumulus, "Nim" is nimbus -- you can read the list in the bottom left corner of the chart) as well as cloud speed and direction.

Oh, and hey I just see now that this chart confirms the wind is using a force scale, which you can get a better description on the bottom right of the chart.

Of notes this month: they had a heat wave to rival our 2009 one, with temperatures reaching 100, 98, 102, and 100 on successive days from July 4-7.(Update! An astute reader says upon further review, that July 6 temperature is 104, not 102 (that looks like a '2' at first blush, but further scrutiny shows it to be a '4', so now we think is 104, not 102!) )

I'm pretty sure there weren't fireworks on Lake Union that year, but if there had been, hoo-boy! Note that those are also 2 p.m. temperatures, so the actual highs might have been hotter. But then again the placement of the thermometer matters and there were few standards back then (although it's not like there was a lot of pavement around to skew the numbers :) )

Now, it's official:

Records became a bit more organized once we got later into the 1870s, and by 1891, official records for Seattle were kept at the Downtown Federal Building. Also, as technology changed, so have the observations. Airports had weather spotters doing all the measurements until the early 1990s when they were phased out for automated weather observing stations.

Now, computers pretty much rule the weather observing world, although humans can still edit and make remarks on weather observations if events are occurring that a computer can't observe. Still, with more data being captured and stored these days, it'll be that much tougher to embellish weather stories to future generations :)