Latest First Frost Ever in Portland

Today I looked out at my still green banana trees and other bushes untouched by frost just a few days before the New Year.  I thought…this is weird!  It is!


Many parts of the Portland Metro area still haven’t seen frost, and when we do finally get a frost, it’ll be the latest ever recorded at PDX.  Those records go back to around 1940.  So yes, a very mild Fall and early Winter so far.  The previous record was December 24th, 1999.

Your next question might be, have we ever gone the ENTIRE winter without frost in Portland.  A “San Diego” winter?  Yes and no.  No, not in the 70+ years at the Portland Airport location.  But before 1940 records were kept officially in downtown Portland.  It appears that about once every 10 years (on average) there is no frost until at least after the New Year at that location.  And at least once we’ve seen no frost the entire winter!

Check out what happened during the Great Depression.  There was a normal late-winter frost on February 14th, 1933.  But that was the last frost of Winter 1932-33.  The following winter (33-34) there was NO frost.  I noticed LOTS of 50+ degree days all through December and January.  Then, we went all the way through the next Fall and early winter with no frost!  Folks were probably thinking the world was falling apart here with a 2nd unprecedented mild winter.  Then finally, on January 3rd, 1935, a frost.  A little less than 3 weeks later a severe (but short) arctic blast hit.  For two days the temperature didn’t climb ABOVE 21 degrees.  Wait, there’s more.  The 3rd day it jumped back to 51 degrees, and 3 days later, on January 24th, it hit 65…in January!  Weird…

Chief Meteorologist Mark Nelsen

110 Responses to Latest First Frost Ever in Portland

  1. Ben T says:

    For a while, it’s seemed like the temperature at night has been between 39-41. Lower more for once!

  2. Garron near Washington Square says:

    Down to 37, hmmm… I might have to cover my tomato plants tonight. I’m surprised that they haven’t issued a frost advisory tonight.
    I drove up to the Women’s forum this afternoon. It was eerily calm, almost no breeze. And I can’t remember the last time I saw the Columbia river looking so glass like. It was as still as a painting today.

  3. chris says:

    Down to 34 already, with a mostly clear sky i think i am going to hit freezing again tonight.

  4. David B. says:

    I’ll go out on a limb and predict an arctic blast (with lowland snow somewhere at least) some time from 2 to 4 weeks in the future. I.e. some time from the 10th to the 24th of next month.

    Why then? First, none is forecast in the next two weeks, so that period is out. Second, it’s an ENSO-neutral winter, and those do tend to have arctic blasts fairly often, and January is the most common month for such things to happen.

    And now that I’ve gone out on that limb, Murphy says the arctic front will probably come barreling through the Fraser and Columbia gorges on the 25th. If this prediction fails, I will quietly try to forget I ever made it. If it comes to pass, I won’t shut up about being right for the rest of the winter 🙂 .

    • Ben T says:

      My prediction last week was in 2-3 weeks we would have an Arctic Blast. So we will see who is right. 🙂

    • W7ENK says:

      I hope you’re right, but I won’t hold my breath… My birthday is just one week beyond the end date you’ve listed, and FWIW, I’ve never had snow on my birthday. Not yet, not once in all of my years so far. One year (1996) had a thin, sublimating layer of dead snow left over in the corners of the yard with cold east winds and clear sunny skies, and another year I saw a few splats mixed in during an absolute deluge of a day, but that’s as close as I’ve ever been. As a kid, snow was always my only birthday wish. I don’t expect this next one to be any different.

  5. 18z GFS
    From looking at 925mb/850mb temps over the Columbia Basin it appears the cold pool will be around for a very long time.

  6. gidrons says:

    The Euro has been consistently advertising high pressure over the west coast. The polar vortex split as hoped, but the cold air dumps way out in the Pacific. The only snow potential the Euro has in the next 10 days would come from the overrunning events that Rob has been monitoring. As always, things can change.

    • wwm says:

      maybe its not just Eric that lives in the dome, maybe ALL of Portland lives in the stupid dome.

    • W7ENK says:

      Yes, it is. You see, this infamous and dreaded dome expands and contracts upon it’s own nefarious will, but it is ALWAYS centered over Milwaukie, very near where I grew up, and only a handful of blocks from where I live now.

      Example from January 11, 2011:

      You can clearly see the effects of the dome, shrunken to a record minimum size, as it deflects freezing rain away from the area below.

      Here’s a visible satellite photo from 2/25/2011:

      Again, you can see clearly see fresh snowfall everywhere around the outside of the dome, but under the dome (which in this case encompased ALL, and ONLY the Portland Metro area) there was zero accumulation.

      One last example, from this last January 17th:

      Snowing EVERYWHERE, except rain only under the cursed dome! Take a close look at where the center of the dome is — hence why I’ve officially titled it the “Milwaukie/Clackamas/Gladstone/Oregon City Anti-Weather Glass Dome.”

      By the way, despite my wonderful and sometimes hilarious abilities with PhotoShop, amazingly none of these images has been altered.

      And you all laugh and think I’m nuts! 😆

    • Hate overrunning snow it only good for a short time than you stuck with a slushy mess. We need a real cold outbreak.

  7. Jethro (Canby ~187') says:

    Mark- NWS records indicate that 1966 didn’t get a first freeze at PDX until Christmas day. :confused:

    Click to access pg65.pdf

  8. 12z GFS/WRF

    I have a feeling things are about to turn very quiet on the blog. Have you ever seen a run more splitty than that? Jeez. Another thing that was very obvious was starting December 30th a fairly strong cold pool develops over the Columbia Basin with persistent 925mb/850mb temps of -5c and -6c respectively. This will keep high temps below freezing and lows in the 20’s which fuels cold and gusty(maybe very strong) east winds through the Gorge. This also may set the stage for a typical overrunning situation since I believe we’ll actually have a cold pool to draw from this time should any decent weather systems approach the area. That is, if they don’t split apart altogether.

    • W7ENK says:

      Split flow? Great! El Niño is definitely dead, and yet somehow his ghost still plagues us with monotony. I should just go into hibernation; wake me up in September when the rains stop and the sun finally comes back out to stay. Too bad by then the sun angle will be too low for any really hot weather… again. 😦

      When can I start pushing the “No 90s in PDX this summer” button again? >_<

    • FWIW, the 12z GEM(Canadian) has not backed off one bit on the ideas of very strong perhaps damaging east wind January 1st – 3rd.

      The GEM could be overdoing things though as GFS/ECMWF are not as aggressive with the idea though. I am merely posting what I see and speculating the possibilities.

    • gidrons says:

      The Euro is sticking with a Rex block

    • Heading to the coast for New Years. That offshore flow should make for a few nice days around Newport.

  9. ECMWF shows fantastic winter weather pattern @240 hr — for the Northeast that is….. No joy in Mudville for at least 1-2 weeks……! Split flow… Yay!

    • Only consolation is…. ‘hawks are going to the superbowl! By that time, I’ll be on vacation, polar vortex will move west over BC, and I’ll be watching them Seahawks kick the krahp out of the broncos and Peyton manning, while sippin some beers as the snow piles up outside. Damn right!

    • Marcus says:

      Anyone know where there is a online meterology school?

    • Garron near Washington Square says:


      This forum here, and the FOX12 DISCUSSION group of facebook are a great place to start. You can ask anything weather related and someone or a hundred will give you links or answer questions and help guide you through the terminology, and graphics.

  10. Anybody else having trouble pulling up the GFS model from the NOAA site this morning? Are there any other good links to the model?

  11. chris says:

    So far up here in the Puget Sound i have made it to freezing 14 times with 21 being my lowest

    • JohnD says:

      Zero freezes at my location (Lair Hill/Johns
      Landing area near So. Waterfront.) The
      winter weather grey-dark-cool-drizzly-snowless-
      joyless syndrome frustrations are always
      compounded by the fact that–seemingly–every
      other place in the surround is enjoying the
      invigoration and scenic ambience of winter
      weather EXCEPT PORTLAND! You would think that
      we would luck out ONCE in a while! And I guess
      we do. It is just that the interim periods are
      simply killers. ESPECIALLY when nothing
      interesting appears to be upstream! Misery loves
      company. At least we have the blog.

    • W7ENK says:

      I wholeheartedly agree, JohnD. One of my weather pet peeves!

    • David B. says:

      I think the only time I’ve seen frost at my place in Seattle this year was back in mid-November (the time it got clear and cold here but mid-level overcast stopped PDX from freezing). Like others have said, just too much clouds and rain, rain, rain for it to get clear and cold at night.

      Think that’s about to change with the forecast drier patterns.

  12. We have had maybe five frosts here so far. I think 27 is my lowest temp so far this winter.

  13. pdxgeologist says:

    No frosts yet here in Panama either.

  14. Phil in Beaverton says:

    I’ve got potato plants that are going like gangbusters. There are some peppers and tomatoes still alive, but, of course, not doing much. Oh, and there’s some nice cilantro out there.

    • W7ENK says:

      I took my tomatoes down at the end of November. Several of the fruits (still green) split from all the rain before I could get to them, so I cut the plants and took the pots in. I do still have onions going though… I keep cutting the greens, and they keep coming back!

    • You can always rely on a winter crop of veggies. We purposely plant a late crop of carrots, beets, mustard greens etc. But usually we try to have them harvestable by the 1st of November. This year they seem to have kept growing. I’ve been getting nice radishes (the ones the slugs don’t get). We got some snow last week but never did freeze.

    • W7ENK says:

      How sad, that we’ve had to resort to talking — the mere fact that we even CAN talk — about our gardening endeavors in what’s supposed to be THE DEAD OF WINTER! Sickening, actually. 😦

  15. chiefWright (Marquam) says:

    I sure hope we’re not too late for some hard freezes this winter! Mild wet winters are really troublesome for lots of agriculture. We depend on those freezes to help manage parasites and other buggers. Sadly, climate is trending in favor of those nasties, which leads to lower yields and higher prices.

  16. W7ENK says:

    Quiet in here… what a boring winter, so far!

    41.5F, that’s where I bottomed out overnight, despite it being mostly clear and the nearly full moon shining when I turned in. It looks like the clouds socked back in and limited radiational cooling, yet again. No frost, we can’t even seem to get a successful fog this season, what’s up with that?!?

    • ocpaul says:

      And it seems the longer you are in a pattern, the more of a lock it is going forward. The last few winters were proof of that. (but not even THIS warm)

  17. Tomorrow I’ll probably have to re-calculate the running monthly average at DLS to see where December 2012 is turning out. It’s going to be quite a bit warmer than climo, I know that….

  18. bgb41 says:

    12/26/2012 Oregon (All) Temperature Summary

    High:50 at DW9913 Cheshire( 466 ft) & Tillamook(63 ft)
    Low: 45 at EW1135 Yachats1(32 ft)

    High:21 at HOWARD Mt Howard(8150 ft)
    Low: 9 at Burns Municipal (4144 ft )

    Largest Diurnal Change: 23 degrees
    Bly Mountain (Or (33/10 ) (4920 ft )

    Heaviest Rainfall:
    1.33″ at FLYNN PRAIRIE(1543ft)

  19. 00z ECMWF
    Looks like sunshine, inversions, and potential for strong cold pool development pattern ahead.

  20. Massive east wind storm on tonight’s 00z GEM(Canadian) This would likely also be a big gap/downslope event for the Washington Cascade Foothills and Puget Sound Lowlands IF it happens….
    2nd run in a row of the GEM hinting at this….

    FCST HR 144 – 180(January 2nd – 3rd)
    *1038mb high over southeast British Columbia moves south strengthening to 1050mb over eastern Oregon! WOW. I estimate a possible PDX-DLS of 15mb.

    *Then a weak 1007mb low/wave approaches with strong easterly gradient in place.

    I’m sure the GEM is overdoing the strength of the ridge, but if not…….

  21. WEATHERDAN says:

    I just got through reading the replies to an earlier post that I had made. I was surprised to say at the least at the vitriol in some of the replies. My only intent was to express my opinion. I thought that was the purpose of this blog. Some of you want snow so bad that if someone dares to say that it doesn’t look like snow is going to get here you go into a frenzy against the offending poster. For the record i respect Mark Nelsen greatly. However I don’t always agree with his forecast. And I have posted so on this blog in the past, and will continue to do so in the future. That is why this blog was started seven years ago. Also for the record I would really like to have an arctic outbreak with lots of snow. And no I am not bitterly crushed that it hasn’t. I was merely expressing my opinion. If any of you were offended by my opinion, deal with it and grow up. And I sincerely hope for your sake that it does snow. I am not bitter at anyone and enjoy reading your posts even when you disagree with me. That is the mark of a mature adult. The ability to engage in civil discourse. Now I do not claim to be an expert on the weather, although I have made a study of it for over 50 years. I wish you all a very happy New Year with plenty of snow and cold.

    • Kyle says:

      Weather Dan. I like you’re posts and I have this to enlighten you.

      These are my own words but here is a link to the site below.

      You’ll be amazed at many of the simular features from back then even though the 1,000AD warming was several degrees hotter for most places.

      There are sections that talk about how the USA and Europe fared during that period.

      Things today are like a *light* version of the 1000AD warming.

      What I mean by *light version* is that for a long stretch there was a 100 year La Nina that never really went away from seabed records that showed cooling off the coast of South America making deserts wetter and The Amazon Rainforest a virtual wasteland when the spigot turned off.

      There are even records of Pre Columbia civilizations the size of McMinnvile Oregon where the people just vanished among the jungles that DID NOT exist back then because of drought.

      Nobody knows what happened to them as there are no signs of struggle or warfare and I think this is the place where they left behind all their belongings or maybe that was another mysterious vanishing.
      There are many records of entire towns throughout earth’s history vanishing without a trace baffling even the most cold hearted scientists and historians out of the lot who know about it.

      Back to the toopic!
      During the 1000AD warming
      Most of the Central and SW of the USA was under mega drought conditions while the PNW was mild and moist with a permanent La Nina.

      Europe and the UK was very warm and wet with hotter summers allowing tropical fruit to grow much further north then today until about the 1200s.

      I suspect that the Pacific Northwest for the most part had mild westerly flow a lot bringing storms and a lot of unusual cloudiness in between even during the summer.

    • Kyle says:

      I do NOT know how anybody can stand such depressing winters with no snow and endless clouds but I think it’s beginning to break a lot of people on here.

      Even Ohio and other cloudy spots of the Great Lakes scored 2X more sun then we have.and they are considered gloomier then Seattle Washington.

      (rest of comment edited…mark)

    • You must be an old guy like me!

  22. David Burnett says:

    I just hope a mild winter doesn’t correspond with a cool summer.

    A nice, hot summer fully compensates for a nasty winter.

    • WEATHERDAN says:

      Actually mild winters quite often lead to hot summers. 57-58, 66-67, 69-70, 76-77, 86-87, 91-92 were all very mild winters that led to hot summers a few months later. This winter is very much like the winter of 66-67. It was very mild and very wet and it led to a very hot and very dry 1967.

  23. Punxsutawney aka HIOPHIL in Hillsboro says:

    I still have a Serrano pepper that is producing and looks pretty good here in Hillsboro. Good thing it’s in a raised bed, otherwise it would have rotted off at the base given that most of my yard has been under water the last month. I’ve had 4 freezes so far this year.

    KHIO has had 9, maybe one or two more.

  24. The “new” weather regime — be it PDO related, climate change, whatever — seems to be characterized by a dearth of offshore flow, year round. Maybe my perception is incorrect…

    • In our neck of the woods, we’ve had lots of the Death Ridge events over the last several years. Resulting in several years of below average precip. I think people are just getting restless for some cold nasty weather. But I will say that the ski areas around here are basking in plenty of snow for this time of year. And that suits me just fine. Now if the coast rivers will just drop a bit more so I can fish my favorite spots for steelhead……

      • Ben T says:

        I know that the temperature in the PAC NW is usually colder in Winters, but I thought we only usually get 1 or 2 semi big winter storms in our area anyways.

  25. Lurkyloo says:

    Spent a year in Hawaii and THAT was mundane weather. Every single day was the same. 70-80 degrees or so. Sun rose and set at the same time — always. Oh, we did have a big “100 year storm” in ’01 — it rained real heavy with big wind for about 3 hours or something. At least we have some hot, mild, cold, windy, and almost-freezing weather here at some point throughout the year. I’ll take it.

    Mud makes me angry, though. Especially in the form of dog prints in my kitchen. Grrr.

  26. paulbeugene says:

    It is time to do this to your banana plants, Mark:

  27. paulbeugene says:

    So far at my house in San Eugenio it has dropped to 31F (last week when it snowed) for a low temp for the winter. I feel sorry for those folks in Puerto Portlando…might as well mix yourself a margarita and raise a toast to the banana plants for longevity…CAUSE THEY ARE GOING TO DIE IN LATER ON IN JANUARY!

  28. ocpaul says:

    I haven’t winterized the hose bibs. I probably won’t. Daffodils are starting to come up. Hard to believe a winter could be worse than the last two. I’m hoping November 2013 will deliver the goods.

  29. ChrisR says:

    I have a question about daily temperature temps. I’ve noticed that for the past few days (at least), tower temps will continue to rise until 12-1 am, rather than rising only until sundown or a little after. Could someone explain why this happens. Thanks

    • Ryan (Walnut Grove) says:

      Warmer air aloft moving in at night will raise the tower temps. We’ve had a couple scenarios this year where warmer air moved in at night warming the tower temps. Not always does night time equate to cooling.

  30. W7ENK says:

    I’ve been wondering about this. Other than 1933, which didn’t hit freezing in Portland, but that was before PDX.

  31. I still have living jalapeno plants w/ peppers on them.

  32. Timmy_Supercell (Klamath Falls @ 4200') says:

    With all the rain that has collected in Portland this year, that statistic didn’t shock me much!

  33. Sara Morris says:

    So when can we expect some frost/snow?

  34. PDX Weather Nut says:

    Sure hope people won’t start with the “end of snow” possibilities already. We need some snow to brighten things up from this dismal rain and cold.

    • Ben T says:

      I sure hope we are not in the same pattern as last year’s winter. Abysmal early winter to so-so later winter into March. We need to take advantage of the sun angle while we have it.

    • pappoose in scappoose says:

      Ya, let’s have some of this!
      Multnomah Falls is nearly frozen

  35. alohabb says:

    I’ ll take 65! Im ready for summer!!!

  36. Ben T says:

    65! I’m fine with 40’s now haha. So what you’re saying is this is weird, but not too abnormal?

  37. Tyler Mode in Battle Ground says:

    I’ve only hit 32 or lower a few times.

    Lots of onshore flow and precip makes it hard to get a frost.

    We haven’t had any 2-4 day period where it has been dry enough to keep the dog at bay too.

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