Yep, it was cold! Coldest September day in at least 71 years in Portland

8:00pm Sunday…

No, you aren’t crazy; today felt like Thanksgiving Day outside.  Cloudy, rain showers at times, a breezy and chilly east wind blowing out of the Gorge etc…

Todays Observed Highs OrWa 2017

Officially it appears Portland only hit 52 degrees at the airport.  That’s ties the all-time coldest September day.  It hit 52 on September 26th 1948 as well.  That’s an average high for the 3rd week of November around here.  For the first time a cold east wind was blowing through the Gorge too, gusts up around 35-40 mph.  This is due to a modified arctic airmass that has spilled south out of Canada.  Compare this to the coldest day each of the past few Septembers

September Coldest Day

We were probably complaining about those lower 60s too…

By the way, there is still an observing site in downtown Portland and the preliminary high there was only 49.  If that holds, that means it may have been the coldest September day in Portland in 145 years!  That said, the downtown temperatures records are a bit sketchier, sometimes on top of very tall buildings and they’ve been moved around quite a bit.   Regardless a high temp around 50 shows how rare it is to see an airmass this cold so early in the season.

Of course it’s been snowing in the mountains since Friday night and a LOT has fallen above 5,000′.  These are estimates, based on pics, ski area reports, and NW Avalanche Center telemetry.  There is

Snow Mt Hood Totals

The next 7 days look uneventful…lots of sunshine and a couple cold mornings ahead.  A few outlying areas could see light frost tomorrow or Tuesday morning.  Just in case, bring in anything that shouldn’t freeze tonight.  No, not pipes/hoses etc…just plants.  We’re talking just a bit of frost touching the plants, not a freeze.

Forecast Tonight Metro

Alright, so the #1 question I keep getting is:


I think the short answer is NO.  What happens in September or October typically doesn’t have any positive correlation to the following winter that I’m aware of.   I’ve never noticed a weather pattern in these months that repeats through the following winter season.  But just for fun, let’s see.

Because this cold/snow event is so early in the fall season, there aren’t many winters to compare this one too.  For example, late September or very early October snow has only been recorded 4 autumn seasons at Government Camp.  3″-1984, 2″-1972, 2″-1971, and then October 4, 2009 when 3″ fell. Then let’s take 1948 as the other year we only hit 52 in Portland in September.  There were 3 very chilly days in late September that year.  So that gives us 5 years with very early season snow at Government Camp and/or very cold lowland temps.

What happened the following winters?

Winter 1948-49 

23″ snow in Portland that year, mainly January and February.  Extremely cold January 1949.  Nov, Dec, & Feb brought big snow to mountains.  466″ total for winter at Santiam Pass.  A very active winter with lots of lowland snow and extremely cold January

Winter 1971-72

Good snow year in Cascades, in fact 3rd snowiest winter at Government Camp.  But that wasn’t reflected down in Portland, 5″ snow for winter season.  An active winter with big mountain snow but nothing too unusual in lowlands.

Winter 1972-73

Extremely cold arctic blast early-mid December, 6″ snow fell in Portland that month, but little/no snow rest of winter.  A relatively dry winter with no real good Cascade snow until later in December (slow ski season start).  Crazy cold early, then a typical winter otherwise.

Winter 1984-85

Big October snow in Cascades and good ski season start.  Then NO snow with a massive ridge overhead all of January.  I remember that one.  Fog or east wind all month (depending on where you lived).  Then tons of February snow in mountains and even some lowland snow that month.  It was a relatively active winter, but with a weird “stoppage” in January.  8″ total in PDX.

Winter 2009-10

Other than a December freeze, a classic mild El Nino winter.  Only one 3 hour snow event (the December 29, 2009 commute debacle) in Portland.  This was the 2010 Whistler Olympics when it was very mild and they didn’t have enough snow at some of the venues.  Cascades didn’t have a very good snow year.  Only 9″ fell at Hood River all winter in the Gorge.  A mild & “boring” winter much of the time.

I suppose one could argue that in each of these “early cold” years at least SOME snow fell in Portland the following winter.  Maybe that’s because this big ridge offshore and cold trough dropping through Canada tends to repeat in the following months?  That’s a possibility.   As mentioned in previous posts, the current pattern is what gave us the record cold/snowy February this year.

One more thought…we’ve now seen three consecutive winters with 6″ or more snowfall at PDX.  The last time we’ve seen FOUR is way back in the mid 1950s.  We’ll see if it happens this year


Chief Meteorologist Mark Nelsen



22 Responses to Yep, it was cold! Coldest September day in at least 71 years in Portland

  1. MasterNate says:

    Everyone, a must read on Cliffs blog this morning. He needs help!

  2. W7ENK says:

    We’re not the only ones getting “record” early cold and snowfall.

    Record early snowfall heralds more later in October

    Last week saw the record broken for the earliest snowfall of winter in Estonia, ERR’s online weather reports.

  3. Roland Derksen says:

    My second wettest September here in BC with 6.35 inches. I agree with Mark- an early cold spell this time of year doesn’t mean a cold winter, although the snowy Halloween of 1984(here) was followed by a cold winter- so it can happen.

  4. MasterNate says:

    Even colder this morning at 31. Most impressive for the first day of October. Looking forward to some fantastic colors arriving soon.

  5. Anomynous says:

    Sunshine with highs in the low 70s at the end of the 7-day is not “back to normal” for the first week of October. Just sayin. Seems like a little bit of wishful thinking Mark.

  6. MasterNate says:

    First frost here this morning. Ice on the roof, yard and cars. Thermo read 33 under covered deck. Rural Canby/Molalla area.

  7. paulbeugene says:

    Interesting that Spokane set new monthly snowfall record, previous record snow was in 1926. In 1926, at same time, was strongest hurricane on record in Azores. And now we have Lorenzo

  8. JERAT416 says:

    It definitely felt like Thanksgiving with the 45 degree rain Sunday morning. I was thinking that before I read anything the weather. Looks like a much drier week coming up now. I’m going to an outdoor event saturday the 5th, so hopefully it ends up not too wet.

  9. Jason Hougak says:

    Mark do you think this coincides with the solar minimum?
    The kids have a walk out of schools for Climate Change which tax payers paid for when they should be inside learning. Now I do think we should control pollution but that we are driving the Climate Change and kids think the life is going to end because of it is brain washing young kids minds. This world could end with an asteroid collision with Earth. Look at our landscape. During the ice age over 1/2 of N. America was under an ice cap… what happened to all the ice… it melted. Because of us… no! The Earth has so many factors and is in a constant Climate Change. Oregon has fossils of tropical plants… what happened to our warm climate… Climate Change! Seriously people, it should be stop pollution instead of brain washing our kids young minds. If our civilization on Earth lasts future wars, etc. they will continue to see Climate Change. The effect of sun and the Earths orbit can dramatically effect or climate. I believe in Climate Change yes, but it’s not due to just our civilization. Stop brain washing children and teach them how to get a job and OFF the STREETS!!!! Our homeless epidemic is WAY more of a PROBLEM and will only get WORSE!!!

    • Gene says:

      Remember that this is a weather blog, not a politics blog

      • W7ENK says:

        Okay, so:

        1) You’re treading dangerously deep into political territory, which is against Mark’s rules, so please stop.

        2) I don’t know where you got the idea that “half of N. America was under an ice cap,” but that simply isn’t true. Not by a long shot. According to most any source I can find, just under 30% of N. America was impacted by glacial ice during the last ice age. For reference, Olympia, on the South end of Puget Sound was the farthest extent of glacial ice on this end of the continent.

        • Jason Hougak says:

          That’s a vague map. It doesn’t even show ice/ glaciers in the inter-mountain west. Just stating that Climate Change has happened since the creation of the world and will continue until our civilization is long gone.

    • ocpaul says:

      They JUST discovered that climate changes. So…

  10. Jason Hougak says:

    First freezing temps of the season. Woodstove with nice crackling fire, I love winter. Let the weather excitement begin.

  11. Paul D says:

    I hope my grass thinks its November and stops growing!

    No complaints about the cooler weather here – keep it coming!

  12. 12:40 AM Temp 46.5, breezy east wind near West Gresham. The east wind has increased noticeably. I’ve only experienced easterlies overnight in September a few times, but that pattern was always with a thermal trough west of the Coast Range and a very warm air mass. It wasn’t with a cold “arctic” trough and strong high pressure sliding down the Rockies giving us a chilly offshore flow. That’s for sure. Speaking of that. This MIGHT be another first for September. Crown Point just hit 50mph at 12:02 AM. I thought this was worth mentioning anyway.

    • JohnD says:

      Looking forward to more of your–always interesting–input as the season evolves Rob!

    • boydo3 says:

      Yeah, usually the east wind this time of year is that dry, warm one. Different this time but it looks like its going back to normal later this week.

  13. Excellent post, Mark!

    January 1949 was on another level in terms of cold!

    Average High: 34
    Average Low: 22
    Lowest Temp: 10

    Average High: 30
    Average Low: 13
    Lowest Temp: -4

    Average High: 37
    Average Low: 23
    Lowest Temp: 12

    SPOKANE (Turned into Little Siberia!)
    Average High: 18
    Average Low: 0
    Lowest Temp: -14

  14. Emmanuel says:

    Good read Mark I like how you added the past winters when we had record cold September’s. My opinion is record low solar minimum will translate to a cold winter this year with good snow amounts in the low land and yes 4 years in a row with 6 or more inches looking forward to see how it plays out whatever happens should be exciting how it plays out. Side Question I have tried doing some research on the winters Columbia river froze up can’t find much curios if it was El Niño time in the solar cycle ect

  15. ocpaul says:

    Every year we get a false start to winter. We get a dump of snow in the Cascades before Thanksgiving. (this is a bit early) Even in the Epic 08′, we were in the fifties at the beginning of December. We had fantastic fall color that year. I got some great photos. Granted, I’d love to see this be a trend. Too early to call
    Now, we’re in the seasons of the year where things start to get interesting

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