Could It Hit 100 This Weekend?

The short answer is YES, it’s possible we hit 100.  But at this point it appears we’ll end up a few degrees short and right now our forecast doesn’t have a triple digit number in it.  Regardless, get ready for a record-breaking hot (and possibly historic) first weekend of June!


  • Get ready for a little RAIN overnight. Anyone north of Salem could see a shower/sprinkles by daybreak.  Cover up anything that shouldn’t get wet!  Not much rain, but a little is possible west of the Cascades.
  • Friday will be much warmer, back up into the mid 80s
  • Saturday & Sunday High temperatures will be somewhere between 94-98 degrees in the Willamette Valley and lowest elevations of SW Washington both days.  This is scorching hot anytime in the summer but especially so this early in the season
  • Oregon Coast This is NOT a pattern for hot weather at the coast.  Likely in the 70s both days out there.
  • Just a two-day heat event Strong onshore flow Monday means highs drop at least 10 degrees, back into the reasonable 80s.  Cooler yet Tuesday and beyond.


Let’s talk about how hot it COULD get this time of year:

Only once in Portland airport’s recorded weather history has the high temperature gone above 98 before the 3rd week of June.  Got that?  At the airport we hit 100 in late May 1983.  There were early season heatwaves in June 2003 and June 1970.  In that 2nd event downtown hit 100 degrees for one day.  You can see that EVERYTHING HAS TO BE JUST “PERFECT” IN THE METEOROLOGICAL WORLD TO GET PORTLAND TO 100 DEGREES BEFORE LATE JUNE.  It’s a tough number to get this early in the season.  For that matter we often go a summer or two without seeing 100 degrees.  We’ve only hit it 4 times in 6 years!


What was similar in those previous events compared to what models are showing for this weekend?  850mb temps (temperature in celsius around 5,000′) were in the low to mid 20s and 500mb heights were around 590dm.  The May 1983 event was crazy with a +26.6 degree reading on the Salem balloon sounding that afternoon.  The long-lived (4 days!) 2003 event peaked at +21.8 degrees.  1970 was 22.4 degrees.  Models have been consistently forecasting +21 to +24 for both days this coming weekend as you can see in the peak of both the GFS and ECMWF 850mb ensemble charts:

Note the ECMWF operational run is just slightly warmer than the average of all its members.  Seems like 100 is a possibility if you consider just this.

But I went back and checked out surface observations with the 1983, 2003, & 1970 events and noticed one big difference.  Each of those produced at least one day, or several in 2003’s case, of stronger offshore flow than what we’re expecting.  East wind made it to PDX each time.  That definitely won’t be happening this time.  The thermal trough will just barely form west of the Cascades, due the upper level ridge being centered to our east.  In fact we’ll be lucky to get any easterly wind even to Troutdale.  Offshore flow looks quite weak this coming weekend.  Here’s the WRF-GFS cross section through Saturday 5pm; Saturday is highlighted in yellow:


That’s a key component with heatwaves here, and even more important in early June.  So I think 98 is about the warmest we’ll see at PDX.

Now it may seem ridiculous to think June 4th or June 5th will see the hottest day of Summer 2016?  Well, let’s assume we hit 98 degrees.  Some years we don’t get above that number and once every few years the hottest day of summer is in June.  So it’s POSSIBLE Saturday or Sunday could be the warmest day of the summer…we can only hope!

Chief Meteorologist Mark Nelsen




92 Responses to Could It Hit 100 This Weekend?

  1. 86 for a high up this way today. Now 80 and I’m opening up the windows and airing the place out.

    • Dizzyland says:

      Good then that 80f will come in and make your house/apartment the same temperature! Yuck! 🙂 Hope you have a good fan or two.

    • Anonymous says:

      Well, it was already 80 inside when I typed that, and from that point on was only going to get cooler outdoors.

  2. Garron 1/3 of a mile from Hillsboro Airport says:

    How does Mark do it? If we don’t hit the century mark today, Mark has made so many temp predictions that mark a milestone for local conditions that I’ve found that Mark, rarely misses the mark for official temperature marks. How does Mark do it? I think that calls for a re-mark from the most official Mark of them all…

    • Paul D says:

      Mark my words, Mark is the man!

    • Joshua Downtown PDX says:

      Mark is a forecasting beast. I notice that the other “meteorologists” in town seemingly trend towards Mark’s numbers days after he posts his forecast. I only look at other forecasts for entertainment purposes. When I want accuracy, I look at Mark’s. His combination of local and overall weather knowledge, and ability to read and interpret small and large-scale weather patterns is untouched in our area.

    • Garron 1/3 of a mile from Hillsboro Airport says:

      Mark Nelsen = to Stephan Hawking.

  3. Lee Wilson says:

    Having hypertension I would state that 106°F is a bit deadly for me.
    N9w you may think the weather stations is off,

    But my phone is showing 102 which is a 4 degree difference.
    I couldn’t stand it out there for another 3 minutes to get a more accurate reading from the phones sensors.

    So, I no longer trust an app that states 90°F
    When it’s hotter that 90.

    I don’t know where that sensor is located but it needs and adjustment or something.

    • muxpux (Longview) says:

      You phone doesn’t have a temperature sensor. Even if it did, much like a regular thermometer there are so many variables. I’m in downtown Portland and my snapchat just said 107

    • Dizzyland says:

      That looks like my weather station but it’s probably in the sun like mine is because that’s the exact reading I got! Weird!

      Okay I got briefly to 107F so I was +1 from you but big deal it was generally the same old song and dance again.

    • Lee Wilson says:

      Actually some phones have humidity and temp as well as a built in barometer.
      Samsung includes these sensors in Therected high end phones .
      So I have humidity, barometer, and temperature sensors .

      IPHONE and others may not have them.
      Not sure on the HTC units.

      My Galaxy Note 3 has a built in compassion as well.
      That is a rare find in any device to have all that crammed into a unit.

      But the sensors are now starting to get left out

      The Galaxy S6 doesn’t have a Physical Compass in it.

      But the way to check such things is to look up the phone you have.

      Foreign example Google sensor technology for Galaxy S6 and or S5.

  4. Joshua Downtown PDX says:

    PDX is running +1 from yesterday at 1:00. Will be interesting to see if we can make it to 100. Gonna be a nail biter.

  5. WEATHERDAN says:

    89 at Noon with a 63 degree DP. Feels hotter than Saturday at this point. Quite amazing to be this hot so early. In the short term a cooling trend should hit us by Monday. But I don’t see a 1983 type of Summer.In 1083 we had a hot May. June was fairly cool but July and August were warm but seldom hot. 30 years of climate change have upped the average temperature to the point where even an average Summer would have been considered warm 50 years ago. Tuesday should be about 88 which is just about perfect for me. 100 is about 10 degrees warmer than I would prefer. I hope you all have a pleasant Sunday. Peace.

  6. Phil says:

    Speaking of heat records… Does anyone know an easy way to get a list of daily records for PDX? Something along the lines of a spreadsheet or csv list, with the date (Jan 1 – Dec 31), the record high (and year), record low (and year), record rainfall, etc?

  7. Paul D says:

    69 at my place in Hillsboro at 5am. Guess we’re not having an overnight low today.

  8. 81 for a high here. Sea breezes got strong to the point of bordering on blustery this afternoon. Forecast to be weaker tomorrow and consequently warmer.

  9. Karen says:

    Please please everyone keep a close eye on your pets…cats, dogs, rabbits, birds whatever critters you have. Keep them cool and keep lots of fresh water for them day and night! And for God’s sake leave them in a cool enviorment at home instead of dragging them around in a hot car with you. Even with the windows down and parking in the shade your car literally gets dangerously like an oven within minutes! Let’s always, especially on hot days of 70-100 degrees….keep our eyes out for any potentially dangerous situations for all critters around us…

  10. Lee Wilson says:

    I am curious as to what kind of strain this is putting on power companies and power producercers to keep up with demands?

    Could we , see black outs due to over loaded systems?
    Or is that just a myth?

    We know about staying cool, but can we lose power from it being to hot?

    • …i dont think it got hot enough to worry about it…

    • Dizzyland says:

      In 1996 or was it 1995 there were blackouts on the west coast that effected several states due to sagging wires and I think some power plants in California offline for regular inspections.

    • Lee Wilson says:

      Yup that is what I am talking about, how hot and how long do we have to be hot for lines to start sagging..106, that sure would seem to get them to start sagging..

      We lost Internet, Comcast lost a node.

  11. EY (Oak Grove) says:

    The three Mesowest stations I see in Milwaukie are (as of this 2:50-ish PM posting):
    EW8319 – 95
    DW6016 – 101
    KC6RZW-10 Milwaukie – 103

    …I’d believe every single one. Except maybe the 95…

  12. Anonymous says:

    95.4° here at 2PM with a light E wind; 100° still seems possible this afternoon.

  13. James Carson says:

    100 at PDX.

    • Paul D says:

      I see 96 at Where do you get your temperature?

    • Joshua Downtown PDX says:

      No 100 at PDX. Hopefully this is the closest we come. 96.2 high temp at my place. Dropped .3 degrees since.

  14. Garron 1/3 of a mile from Hillsboro Airport says:

    Judging by the mass exodus on Sunset highway I witnessed this morning, I’d say the message got out! The grocery stores were no treat either!

    • Garron 1/3 of a mile from Hillsboro Airport says:

      Just wondering if the fact that the hot air mass made it to places like Tillamook to Astoria this early afternoon if that is going to make it easier for us to hit that 100 degree mark today? It’s already 90 degree before 1PM…

    • Paul D says:

      Great day to stay home! No traffic, no crowds, no stress!

  15. MJ says:

    Really scorching here already. SItting at 85F and headed for 100.
    And on a unrelated note, the bees were released, then I smothered them with a can of raid. Game Over 🙂

  16. Kohodatek says:

    After the heatwave in May of ’83 we had the most peculiar summer that I have ever seen, rain and thunderstorms for most of the summer. I have had 100 degrees in mid-May and that came with compression heating and a strong east wind, we were in the 90’s by 10 AM.

    • Yeah, 1983 was weird with that heatwave in late May, but for me summer 1986 was also strange. After a fairly sunny June (especially the first half of the month) July basically went into the tank with cool, mostly cloudy days. But August 1986 was great- almost no rain at all.
      at all.

    • whoops- too many “at alls”!

  17. Marc (Brush Prairie, WA) says:

    Last night shows that just because it’s early June, temperatures at night can stay very warm.

    • muxpux (Longview) says:

      Yeah, wow. Low of 66 here in Kelso. Already 70 at 8:40am

    • Joshua Downtown PDX says:

      Yep. It looks like PDX broke the record for warmest minimum temperature for the date. It is very likely that the next few days will all be record breaking as well. Heck, if it wasn’t for a 71 and 69 degree low last year in late June, we would likely break the all-time June record. We still might.

    • Mark Nelsen says:

      Yes, nights are longer than in August so there’s no reason we can’t have the warmest nights of summer with a heatwave this extreme in early June. That said, the land is cooler than what we’d see in mid/late July so I suppose that’s one reason we have consistently warmer overnight temps in July too

    • It’s a three-way seasonal game between sun angle, airmass temperature, and the latent temps of the land/water.

  18. Jason Hougak says:

    Will the crude oil derailment start a Gorge wildfire… what a nightmare for the Columbia River Gorge

  19. Paul D says:

    No more triple digit in the forecast! But now Saturday is the hotter day.

    Very interesting….

  20. My alter ego says:

    Nice weather today. Almost perfect for me in fact. But a little too warm for me this weekend. My comfort zone is 85-92. 100 is overdoing it a bit. That said I would rather deal with the heat then a crummy weather weekend in Summer. For me tha t would be rainy with highs in the 60,s. But cheer up you rain lovers the start of the cool and wet season is only 4.5 months away. Stay cool my friends. Peace.

  21. Joshua Downtown PDX says:

    Let’s play the opposite end of he spectrum game.. if we hit 100 this weekend, the cold equivalent would be a 42 degree high temperature. Ha. We can’t even muster anything remotely close to that for the low temperature. To those of you sadistic heat lovers- enjoy the next few days.

    • Paul D says:

      So we’ll be about 30 over normal. When does it ever go to 30 under normal? Very rare – a lot less than 30 over.

      It just isn’t fair….

  22. Paul D says:

    Since it hit 100 in 2009, 2012 & 2015, that means it can’t hit 100 again until 2018, so it’s not going to this weekend.

    • Mark Nelsen says:

      I LOVE that reasoning!

    • Paul D says:

      I see the 7-day forecast has been changed to reflect my reasoning. You’re welcome. 🙂

    • Garron 1/3 of a mile from Hillsboro Airport says:

      Yes, I like that reasoning too, but it’s already 90 at noon, sooooo… Like Mark said, this COULD be our hottest/heatwave for the entire summer, and it is still spring. Looks like normal summer is coming though!

  23. Boring Oregon says:

    0.29in of rain overnight. Ground is still wet. Hopefully it’s enough to get the plants through the heat this weekend.

  24. Jason Hougak says:

    I’m as crazy about hot weather as Clark is about Uncle Eddy

    Too bad my Rogue River float is a month away… take me to the river

    • runrain says:

      That would be Cousin Eddie. And that there is what you call an RV.

      Take me to the river, wash me in the water….

    • Garron 1/3 of a mile from Hillsboro Airport says:

      Don’t forget, you don’t need a BBQ Clark, when it’s this hot round here we just cook this here chicken on a rock!

  25. We already have more rain here in this June that all of June 2015! 🙂 But , seriously I am intrested in seeing how this heat wave will develop. I could see 90 here in Sunday.

  26. runrain says:

    I see Mark has joined in the triple digits club for Sunday. And why not. Looks so much neater than a 98 or 99. I also see a 91 for Monday so this should be our first official Heatwave of the summer.

    • Paul D says:

      Not liking that three digit number on Sunday.

      I see five days at 85+, so I declare it a heat wave IMO (I know Mark won’t agree).

  27. pappoose in scappoose says:

    Public Information Statement
    National Weather Service Portland OR
    1235 PM PDT Thu Jun 2 2016


  28. W7ENK says:

    This should make camping in the Deschutes River Canyon an interesting experience… Maybe I can top the 115 I was in down there end of June 2008.

    That was the weekend leading into some epic thunderstorms that Sunday evening.

    • Joshua Downtown PDX says:

      That would be a heat wave in LA in August. So yea, I think it would qualify in Portland in the beginning of June.

    • schmit44 says:

      I am sure your station in Milwaukie will hit 105 while all surrounding stations will be 98-101. Happens every time.

  29. runrain says:

    I see the NWS is going with 90-100-100-90 for Fri-Mon, so I guess that qualifies the upcoming warmth as a heat wave (at least three consecutive days over 90).

  30. Jesse-SW Portland Suburbs says:

    Mark, I think by late May 1998 you actually mean late May 1983, in which PDX hit their earliest 100 on record on May 28th. That was followed by a wonderfully cool summer, possible analog? 😉

    Spring 1998 had another notable weather event, in which PDX hit their earliest 90 on record on April 30th. Perhaps you were getting the two events confused.

    • Mark Nelsen says:

      Jesse! It’s been too long. You are right of course. I meant the May 1983 event and had it right farther down in the post. It’s corrected.

    • runrain says:

      I remember that April 30th, 1998 event, mostly because it was followed by an outstanding thunderstorm that rolled right out of the Cascades and into the Portland area.

    • Yes, it’s good you corrected it to May 1983. Late May 1998, saw very different weather- especially for me. We had 3 days of very wet weather then where I live.

  31. boninepaul says:

    Mark, you are the bomb on heatwaves so i take your prognostication very seriously. I remember how well you forecast the 103, 106, 106 in 2009. By the way on the the last day of that heatwave I hit 108ºF in my north Portland backyard. And I lost more plants in that heatwave than the all the plants I’ve lost in the last 10 years of winters. Luckily, this time there’s still a little residual soil moisture. Remarkable how insanely early everything is in my garden. As a professional for 30 years I can say it is unprecedented.

  32. Garron 1/3 of a mile from Hillsboro Airport says:

    Well, it WOULD have been cooler at the beach this weekend, but somebody spilled the triple digit beans, and the mass exodus to the beach will make it about 97.8 D/F as you will be sharing every square inch of the beach with another sweaty human!

  33. umpire says:

    Groan – summer softball season starts on Sunday. Four games on Sunday; at least I start in the morning.

  34. . says:

    Ugh, dear God make it stop. WAY too early for this mess!!!

  35. Showers have been falling here since 3 pm. I’m happy to see we’ll get some rain before the heat comes. As a kid back in June 1970, I do remember the thermometer reach 96F on June 2nd here in Vancouver. That was the hottest day all that summer.

  36. Paul D says:

    This weekend will be the warmest for the entire summer?!? I sure hope that’s right. It would also be nice if it’s the last time we hit 90.

  37. Tyler Mode in Battle Ground says:

    That’s too hot! I think I’ll go to Yellowstone…

    Meanwhile, bumping my halo pic back up into this thread 🙂

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