August 22, 2016

The Portland Hot Box

The questions that everyone should ask is why would anyone live in Portland, Oregon during the summer, when Seattle and Puget Sound is so close?

Portland, located in the northern Willamette Valley, is a hot box, frequently 5-10F warmer than the more temperate Seattle, which is cooled by the Sound, Strait and the Pacific.

Let's review the temperature data, and those in Portland will be excused for skipping the details.

 Here is a plot of the temperatures at Sea Tac (red) and Portland (green) airports. Portland is warmer virtually every day, and sometimes by a considerable amount.  Portland reaches the 90s F quite frequently

How about the average maximum temperature over the past month?   Mid to upper 70s in Seattle, mid to upper 80s in Portland.

Extreme temperatures?   Here is a plot of daily highs--yellow lines-- at Portland and Seattle.  In Portland, many days have daily records above 100F in mid-summer, several as high as 105-107.

In contrast,  Seattle almost never gets to 100F (one day).

OK, it is clear.  Portland is a hellishly warm place during the summer.  But why?   The key is they have poor access to the cool water and thus natural air conditioning of the Pacific.  As shown by the terrain map, Portland is in a topographic "bowl", with moderate terrain on all sides.    Hard for cool air from the Pacific to get to the city.  The Columbia and Willamette rivers are too narrow to do much good.

In contrast, Seattle has direct access to Puget Sound, the Strait is close, and there is a sea level path to the ocean.

Portland Purgatory versus Seattle Cool. Portland also has weird donuts. (see below, so hot down there they put bacon on the donuts)

 The only thing that makes Portland livable is a ready supply of chilled microbrews.  Without them, Portland would be abandoned during the summer.


  1. Your opening question is a joke, right? How many people do you know who "summer"?

    Also, I'm going to go out on a limb and say Portland has a more moderate summer overall than the vast majority of the country.

  2. Funny. It's not like Portland is Phoenix!
    But I didn't realize the contrast was that much--- in Portland, just get some AC and all is fine.

  3. 'Weird donuts'? Voodoo Donuts is far superior than our reigning local doughnut chain, Top Pot, in terms of selection, creativity, in addition to its selection of vegan donuts, (not that it means those ones are actually any healthier.) BUT, Top Pot already sells a bacon maple bar, so please do better research before you make claims about those 'strange' donuts pictured in your blog.

  4. Q: "The questions that everyone should ask is why would anyone live in Portland, Oregon during the summer, when Seattle and Puget Sound is so close?"
    A1: Warm will help survive the coming cooling.
    A2: No sales tax

  5. conversely, Portland is often much colder in winter. Notorious ice storms

  6. I love Portland but let's be honest- temps in the high 80's and 90's (and 100's!) west of the Cascades can feel uncomfortable. The numbers aren't high enough to get sympathy from people living in the desert SW, but it's still way too hot for my liking, and substantially (surprisingly so) warmer than temps here in Bellingham.

  7. Peaches and Apricots. Eggplant. Better tomatoes. Pinot Noir. IIRC, upwards of several hundres hours of better degree days.

  8. People in Portland also look south and say "at least it's not as hot as Medford!"..

  9. The questions that everyone should ask is why would anyone live in Portland, Oregon during the summer, when Seattle and Puget Sound is so close?

    One word: Traffic

    Although...Portland is working really hard to catch up to Seattle. Arg.

  10. There used to be a big difference in traffic.
    Now both areas suck.

  11. If your standard of comparison is Seattle, pretty much any major US city will look like a "hot box". Portland is actually one of the coolest major US cities in the summer. I think it's #3 on that list. #1 is of course San Francisco and #2 is Seattle. That said, it *is* indeed significantly warmer than Seattle (in the summer; their winters average slightly cooler). I've lived there and while there is a lot to miss about Portland, the more frequent and severe heat waves they experience are not one of those things.

  12. I live just north of Vancouver, WA, and thankfully we get a wonderful breeze every night, even on hot summer nights. Because we live on a ridge (there's a reason my town is called Ridgefield), we still get hot like in Portland, but we are able to cool off at night. My favorite season here is the fall, with the cool crisp mornings and warmer afternoon temps.

    Although last weekend was crazy hot here (over 100), this summer has mostly been very mild. Just a few weeks ago, it barely got to 70 degrees and was raining. The leaves here have already started turning because of the mostly mild summer. August has always been our hottest month, so it's not surprising when it gets hot. I still remember in summer of 2009, when it got to 113 degrees. Compared to the 102 we had last weekend, that's nothing. Plus I have AC, so I stayed comfortably away from the heat.

  13. Portland is horrible, especially in the summer. Stay in Seattle if you care about the children and staying safe from terrorists.

  14. Extending this logic, we should all move to Vancouver, BC, which in the summer is often almost as much cooler than Seattle as Portland is warmer.

  15. Please tell me all of you realize this is simply satire.

    1. Sadly, I don't think any of them realize it. Most of the responses are comical, and not in a good way. It's scary that people can be so desperately clueless, or just feel the need to be outwardly argumentative about such an insignificant and light hearted subject. Wow.

  16. Ya it can get considerably hotter than Seattle but its only a couple of hours drive to the much cooler Oregon Coast. Although, I was in Newport last Friday at the peak of the heat wave and even the coast had a rare hot day. I have never seen so many people on Oregon beaches and even swimming in the freezing cold ocean! It almost hit 100° and it really felt more like California on the beaches that day.

  17. Seattle has a "summer"??? Couldn't tell when I was there in July! Mark Nelsen - KPTV/KPDX TV, Portland

  18. The question everyone should ask is why would anyone live in Seattle when they could live in more temperate Bellingham? It's almost always 5 degrees F cooler in Bellingham than it is in sweltering Seattle! Not to mention the traffic...

  19. Top 10 Chill Cities:

    1. Seattle

    2. Portland, Ore.

    3. San Francisco

    4. Denver

    5. San Jose, Calif.

    6. Buffalo

    7. Salk Lake City

    8. Milwaukee

    9. Detroit

    10. Pittsburgh

    Top 10 Hottest Cities:

    1. Phoenix

    2. Las Vegas

    3. Dallas

    4. Houston

    5. Austin

    6. San Antonio

    7. Miami

    8. New Orleans

    9. Orlando

    10. Tampa

  20. ^^^Well played Mr.s Nelsen! Most of actually love our hot box down here, plus I can actually grow corn and tomatoes in my garden and they turn color and ripen! I got one of those room to room AC's and have rarely been too hot, unless we get a rare muggy day. Usually the air is really dry on warm days, and we cool off at night enough to mitigate the day time heating.

  21. The first two comments' indignation about artisinal donuts and accusing Cliff of classism because he used the word "summer" in an insufficiently enlightened manner. Man! Imagine if we had REAL problems to deal with like most of the rest of humanity.
    lol this is definitely a PNW blog.

  22. I lived in Renton and Kent for 16 years before moving to Clark County in 2003. I grew up in California and experienced Los Angeles as well as Bakersfield summers. Portland is nothing compared to Bakersfield except when the heat gets to all time record highs, though it can be comparable to Los Angeles.

    As you know, moist air holds more heat than dry air, but we have the imprecise measure of temperature to equate to the heat content in the air. The real heat content of damp air is much higher than the heat content of dry air at the same temperature. I've been to both Phoenix and Houston in the summer and though Phoenix was pushing 120F and Houston was only in the high 90s, Houston had more heat stored in the air that was not reflected in the thermometer. This is why the heat index measure exists.

    Seattle summers are much damper than Portland. The hotter it gets here, the drier it gets. It's 90F here right now, but only 30% humidity. It will drop to about 20% when the temps go up later this week.

    Personally I can handle 95 and dry much easier than I can handle 85 and damp. When I worked in my yard in Seattle when it was in the 80s, I'd just about fall over from heat stroke after 1/2 hour, but here in the Portland area I can tolerate 90s outside much easier, though I try to avoid working in the sun.

    I moved to the NW because I hate hot weather in general and I love 3 of the 4 seasons here, but I will take dry heat over damp heat any day.

  23. Cliff, I can vouch for this personally. I moved from Tacoma to Portland a few years ago and found that it was indeed noticeably hotter in the Summer than the Puget Sound Region. Last summer with the"blob" in place, it was almost unbearable, with several consecutive days topping out over 100 degrees. The rivers are a sad substitute for the Sound, both in temperature control and scenic beauty!

    Conversely, in the winter Portland is often colder than Seattle, especially when we get the east wind blowing cold air from the east side out of the Gorge.

  24. At least it's safe to venture out in small boats on the Columbia or even swim. Up here near Seattle, you've got to deal with Orcas, many of which are known to be voracious killers. As in Killer Whales. I've heard stories of them silently sneaking into tiny harbors beneath pleasure boats to go crazy killing seals or anything that looks like a seal.

    If you think Great White sharks are bad, you don't want to watch two Orcas tearing a seal to bits. Or one of those supposedly bad-ass sharks. They'll even launch themselves up on shore to grab delicious critters and drag them back into the sea. Worse than Florida's alligators by far. Bloody horrible.

    In Portland, you can dip your toe into the water without tempting one of those monsters of the deep to race in and swallow you whole. Which they can definitely do.

    Go Portland.


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