Puget Sound Summer 2010 (2020 applicable)

(focus on the South Sound OLY TAC area)

SUMMER 2010 WAS NEARLY A TOTAL BUST. That's as of the official end of Summer, September 21.... See explanatory note* re: my coined term "THE OLY-TAC AREA".........

In fact, a January 19, 2011 story in the Olympian newspaper quoted a climate researcher at the University of Washington, whose data claimed that 2010 as a whole had suffered under 107 days of "heavy fog" as opposed to a normal of 89 days, and that 2010 had in fact featured the most foggy summer on record, and not only for Olympia, but for many cities in the Northwest, including Portland. Note: the research definition of heavy fog included the "low cloud" decks for which the Northwest is so notorious.

DISCUSSION: Many folks from sunnier climes like to think that a good Summer begins with an April that shows up with some encouraging sunny, warm days at least a few times, followed by a May featuring an encouraging spell of warm, sunny days at least once. But Spring 2010 in the Puget Sound area was rather depressing.

April 2010: at Sea-Tac the month's highest temperature was a measely 70 degrees one time, with zero days rated as clear, and only 8 days with no measureable rain.

May: at Sea-Tac the month's highest was a cool 72 degrees, with only 4 days rated as clear, and zero rated as cloudless. In Olympia there were only seven days with no measureable rain, and over 4 inches of rain fell, breaking records.

June: all around the Puget Sound, the month of June was especially disappointing to those looking forward to a nice Summer. At Sea-Tac the two warmest days were only 77 and 74 degrees, with only a single day rated as clear, and zero days rated as cloudless. In Olympia, the rain continued to pelt down with record amounts, 3.34 inches in June. You started hearing people referrring to "June-uary" because the month seemed more like winter than nearly-summer!


July 2010: finally summer arrived. Sea-Tac reported the Spring/Summer's first cloudless days, five of them. It was a happy thing to see sunshine flooding down all day long at long last. The month's high temperatures were 90, 93 and 95 at Sea-Tac, with 11 days rated as clear. There were still six days having measureable rainfall. Nevertheless, overall the month felt quite dry, and with a fair number of clear days, residents felt cheered, and ready for August to get even more summery, as is often the case around the Sound.

August 2010: the area's Last Best Hope for a "real" Summer month did not materialize. Sea-Tac's three hottest days were 91, 95 and 96. There were six days with measureable rain. Only 9 days rated as clear, and only four of them were rated cloudless. The month ended on a dismal note, with a dark, cloudy day full of rain and a high temperature not even reaching 60 degrees.

September 1-21, 2010: I rate up until the official ending of summer, September 21st. At Sea-Tac, the end of summer was marked by lots of rain and clouds. A few times summer struggled to get back into the game, with highs of 84, 77, and 72. The were 12 days with measureable rain during the first 21 days of September. Worse, there were NO days rated as clear, and worse yet, only three days were even rated as "partly cloudy."

Summer 2010 Summary: "SLOW TO START, QUICK TO END" characterized Summer 2010 around the Puget Sound. There were only a couple spells qualifying to be called "heat waves," and they were not lengthy....In Olympia the year's high temperature was a 97 set in August, and the second hottest being 95. But even in Olympia, there were only 7 days in the whole year hitting 90 or above. At Sea-Tac, there were only six days hitting 90 or above. September in Olympia recorded nearly five inches of rain, nearly all of that fallling when it was still suppposed to be summertime; this broke many long-standing records. To this writer, one of the gloomiest statistics of the 2010 Spring/Summer were the cloudiness ones-- there were only nine days in the entire period of Spring and Summer that were rated as cloudless days, and only 25 days out of 172 days rated as "clear" (that's less than 15% in what is supposed to be the sunniest time of year around Puget Sound)...... November 3, 2010 Addendum-- Surprising news, the Puget Sound turned around the gloomy summer by having a pretty decent Indian Summer period in October, and then astounding everyone by tying the all-time RECORD HIGH FOR NOVEMBER! That was a one-day long, freak heatwave on November 2, where Sea-Tac saw an official 74 degrees, tying the old record, which had stood for 61 years (since 1949)...

Tacoma, Washington vs. Eugene, Oregon to illustrate

Summary: if one moves south from Puget Sound into the Southern Willamette Valley in Oregon, summertimes are much more sunny and also are consistently warmer. Summer 2010 illustrates this climatic pattern very well. The pattern remains true as of late 2019.

In August 2010 the Sea-Tac airport featured the summer's best heat wave, a mid-month one where for five consecutive days it was hot and sunny-- 86, 95, 96, 91 and 89, but overall August managed only 9 days rated as "clear," and only 4 days rated as cloudless.... Meanwhile, in the Southern Willamette Valley it was considerably more summery-- in Eugene, where I used to live, the heat wave stretched out longer, with highs of 89, 95, 101, 92, 95 and 90, and the month had 12 clear days and zero cloudy days. Both stations reported somewhat sub-normal rainfall for the month, but nevertheless they both had several rainy/misty days that got outdoor projects wet, especially in Tacoma/Olympia (8 rainy days officially, and 9-10 in Olympia by my guesstimate). At Sea-Tac, the last day of August brought a really BAD sign of things to come, with a high of only 59 degrees and 0.40 inches of rain! While that last day also brought rain and cooler temperatures to Eugene, it was warmer with much lighter rainfall.

Technical Note: * CLEAR. National Weather Service (NWS) official rating system of "clear" is a ten-point system, where 0-3 clouds get the "clear" designation. Note that during the very long daytimes of mid-summer, this means that several hours of a day can be worse than "clear," and the day still get a rating of "clear."

** NOTE: SKY CLOUDINESS DATA: I used data from Sea-Tac International Airport. I've observed numerous anomalies in the data from Olympia, especially in what appears to be a pattern of inaccuracy in the reporting of sky cloudiness due to the type of automated instrumentation used at the Olympia Airport. Thus, I use Sea Tac cloudiness data, which is collected by real people on a 365-day per year basis and is much more reliable.....To extrapolate conditions in Olympia, we look to the long-term averages, which show that Olympia is considerably wetter than Sea-Tac (Olympia yearly rainfall is somewhat over 50 inches, where Sea-Tac yearly is somewhat under 40 inches). We also know that Sea-Tac lies on the southern fringe of the Olympia Mountain rain shadow, whereas Olympia is far enough south to be missing the rain shadow effect. Generally speaking, then, Sea-Tac shows an overall pattern of less rainfall than Olympia, and probably also should show somewhat less cloudiness. Image below: a late-afternoon satellite image from mid-summer, showing the flux of cool coastal air and low clouds funneling up from the Coast and hanging right over the Olympia area.


It's rarely sunny? "Good," they say, "I hate that bright, glarey Sun.".. It's rainy almost all the time in the winter, and often even in the summertime? "Good," they say, "I love all that green! I love the moist-feeling air! I love the rain-washed smell of things!"... Such well-adjusted folk say the rain doesn't really prevent them from enjoying their outdoor activities, many are observed walking around in 40-50 degree temps in the rain, hatless and wearing just normal shoes and a T-shirt!.... It rarely snows in the winter? "Great," they say, "I hate the snow.".... Temperatures are often cool and windy, even in the summer? they say, "Wow, we have such a MILD climate! One of the BEST climates on Earth!"

Copyright 2010=2019 by Bruce B. Johnson M.A.

Notes: OLY-TAC. * while my hope as a weather reporter had originally been to focus only on the Olympia/Lacey/Tumwater area, that has proved impossible due to a data accuracy factor... in search of the best data, I now present the sky cover data from Sea-Tac International Airport, 50 miles north of Olympia, while the rainfall data is mostly from from Olympia itself (the Olympia Airport's automated station). I coined the term "OLY TAC' to delineate this area... This is not an entirely good way to do things, and I'm forced to factor in some guesstimates because Olympia often has more persistent low clouds than anywhere else around the Puget Sound, to name just one of the discrepancies. (eg. in the satellite image above it's 3pm on a late summer afternoon, with warm sunshine prevailing all over the Northwest-- except for a blob of low clouds hanging right over Olympia!)..... And while Olympia often gets hotter in the summer months than Sea-Tac, it is also generally quite a lot more rainy (yearly, about 52-53 inches vs. only 38-40 at Sea-Tac). All that extra rain produces more cloudy/foggy/misty days with drizzle than at Sea-Tac, as a generality, but a difficult one to measure and quantify. But it's easy to observe the common pattern during the summer months that you leave Olympia under gray overcast skies and drive out from under the clouds into sunshine by the time you reach Tacoma.



Want to respond to this page?

E-mailer: click for a direct link Brucej@oregonphotos.com


Back to Washington Climate Main Page

Back to Main Oregon Climate Page

Back to OregonPhotos Main Page


Page Last Revised January 24, 2018. Reviewed December 2019

The Puget Sound's Notorious See-Saw Effect is strong as Summer 2010 Poops Out: the weather is mostly cool and cloudy, with a couple brief glimpses of Summertime:

August 25 at Sea-Tac = high 86, but the very next day, high only 69, and temps stay very cool until Sept. 3, when it zooms to 84, but the very next day high is only 67, and the highest after that, up until the official end of summer, is only 72, on one single occasion.

Down in the Southern Willamette Valley the effect is less pronounced and summer temperatures linger longer: August 25 has a high of 97, and the next day cooled radically, just like around Puget Sound, but down to a still-warm 77. ...September 3 saw a high of 90, cooling to 74 the next day, but in Eugene summer wasn't over yet, with September 14th seeing a pleasing 81, and the 16th approaching 80 with a nice 78 degree day.