The historic July 2022 heatwave has ended

9pm Monday…

What a terrible week to be without air conditioning in western Oregon or southwest Washington. I was off on vacation (Leavenworth WA & B.C.), and I can tell you it was hot everywhere in Cascadia…except along the coastal beaches.


  • The last week of July 2022 will go down in history featuring one of our greatest heatwaves
  • Portland, Seattle, Eugene, & Medford saw their hottest week on record, Salem, Pendleton, & Redmond 2nd hottest
  • As expected, nighttime temperatures were record-breaking warm due to high humidity
  • Humidity was quite high; one of the “sweatiest” heatwaves I’ve seen in our area

All the Stats

Today’s high in Portland was 89 degrees, our first day back in the 80s since Saturday the 23rd. You just endured the warmest/hottest week on record in Portland. Take any 7 days in Portland’s history, adding the 14 highs/lows, then divide by 14. You get the average temperature for those 7 days. The 83.4 you see below is the highest on record


This included a record 7 consecutive days at/above 95 degrees


Salem was worse, enduring 7 days at/above 98 degrees! In Portland is was NOT the longest spell of 90+ days though. That record is from 2009


We hit 100 degrees 3 times, peaking out at 102 on 2 separate days. Note no “extreme” hot days (103 or higher) this time around west of the Cascades. As expected ahead of the heatwave, a weak onshore flow was present most of the past week (except Tuesday). Believe it or not, that means we could have been quite a bit hotter.


In my view, the most stunning part of this heat wave is what happened overhead. The 850mb temperatures (in Celsius around 5,000′) on the Salem weather balloon soundings were record warm/hot. It peaked at 25.4 on Tuesday and Wednesday, 28.2 on Thursday, 26.8 on Friday, 27.0 Saturday, & 26.2 on Sunday. That Thursday number is higher than anything previously seen in either July or August (27.6 deg). So it’s fair to say this was the hottest overhead atmosphere we’ve seen in these two months. IF WE HAD SEEN OFFSHORE (EASTERLY) FLOW last week, temperatures would have peaked between 105-109. I think it’s especially interesting that the atmosphere got so hot considering 500 millibar maps were not shockingly warm. Highest heights were 590-595dm during that time.

East of the Cascades the hottest air DID surface Thursday, Friday, & Saturday. Take a look at the high of 112 at The Dalles and 109 at Redmond on Friday the 29th. If not for last year’s heatwave, those would have been all-time records. What’s the chance of setting all-time records in 2 consecutive years? It’s almost as if our climate is changing and warming (it is!).


Of course what made this heatwave really bad was the lack of overnight cooling and high relative humidity. Dewpoint is the best measure of moisture in the air we breath. It was regularly between 60-70 degrees, especially the 2nd half of the week through Saturday. There were plenty of spots in the hills with dewpoints at or even slightly above 70 (due to vegetation). The last time Portland dropped below 69 degrees was Thursday morning! I grew up and started my career with the mantra “you don’t need A.C. in Portland”. That’s no longer the case. Anyone in the urban area should have at least a room air conditioner for sleeping.


Finally, July ended up the 4th warmest month on record in Portland, only eclipsed by July 1985, 2015, & 2018. Those months were generally warmer across the entire month. Notice we were near normal until the heatwave arrived. This month just barely edged out August 2017.


That’s it for now. August is here and warm temperatures continue through the foreseeable future. A brief heatwave is possible Saturday through Monday with highs in the 90-95 degree range. Humidity should be LOW with that heat too. I see dewpoints mainly in the 50s.

Enjoy the cooldown through Friday!

47 Responses to The historic July 2022 heatwave has ended

  1. tim says:

    Dew points will be between 65-75 Saturday through Monday. currently dew point is a comfortable 55.

    • Joshua Lake Oswego says:

      Dew points will be nowhere near that high this weekend. Probably mid-40s. We will cool off much better at night than during the previous heatwave.

      • tim says:

        Forecast lows for pdx during this heat wave is between 64-67 that’s only a fews degrees cooler than the last heatwave 67-69 hardly a noticeable difference.

        • Joshua Lake Oswego says:

          PDX and some of the immediate metro area might stay warm, but everywhere outside of that will
          be much cooler this time.

      • Snomanski says:

        Inshallah you are right. One thing is certain: these recent summers are the new normal.

    • Andy says:

      Temperatures over the decades are much higher around Portland due to population growth. Basically, an urban heat island. Areas away from urban areas cool of much faster. This is a scientific fact in microclimate analysis.

      • Peter Christenson says:

        Are you asserting that rural areas have not warmed up over the decades or that they are just cooler than downtown. I hope the latter, because that is the fact.

      • Peter Christenson says:

        I can vouch for the fact that Rhododendron has gotten significantly warmer since 1990 or so. There used to be a motel at 1900 feet (right across from the DQ) named “Snow Line Motel.” If only. The motel has been replaced (appropriately) by a rather nice weed store.

  2. Bethany250ft says:

    Looks like we could see some thunderstorms when that cutoff low comes inland

  3. Roland Derksen says:

    It’s interesting to see that the mean temperature in the last week of July 2022 was warmer than the last week of July 2009 in Portland, as well as in my area I.think warmer overnight temperatures was the factor responsible for that.

  4. tim says:

    Today’s cpc week 3 and 4 outlook has us above normal temps so no signs of a early fall unfortunately for those who want it.

    • MasterNate says:

      Everyone knows that those outlooks change with the wind. Winter is coming.

      • tim says:

        Winter is coming yes but not in late August early September that makes no sense. No sign of a early fall is what I said.

    • Zach says:

      The CPC outlooks is as good as flipping a coin. Completely worthless.

      • tim says:

        I don’t think we’re gonna have a cool August there’s no current model data that shows that right now but the opposite instead.

    • Anonymous says:

      the cpc said we would have a hot June and a hot may.

  5. tim says:

    Current temp 65 dew point 52 nice, this weekend dew points near 70 again with the heat, yuk.

  6. Opie says:

    I thought I’d share some climate trivia from the PDX station, 1938 – present

    Trends in monthly average Tmax
    Top 4 months:
    August: +0.6 F/decade
    January +0.5 F/decade
    June,July +0.3 F/decade

    December: -0.2 F/decade

    (Source – Climate at a Glance)

  7. beaver1974 says:

    Excellent work. Glad you have finally come around-Global Warming is here and it has been for a longtime now. I, too, grew up here: “You don’t need AC.” Not anymore.

  8. tim says:

    Cfs model is showing a hot second half of August which is the complete opposite of last August so most likely it’s gonna happen, gfs 12z is hinting at that too.

  9. Zach says:

    The summer climate in Portland has felt more like Medford the past three years. I remember summer of 2019 was really nice with only 9 or 10 days at or above 90F.

  10. Weatherdan says:

    88 at 3:30PM. Not too bad. Lots of heat coming our way in the next 16 days. And probably more after that. Climate change is here, and not going away anytime soon. Autumn however will eventually arrive and with it the rain and the cold. In the mean time enjoy the sunshine. Peace.

  11. Joshua Lake Oswego says:

    Looking at models, we could easily go a period of 25+ days with 24 of them having above average highs. Most of them well above.

    On another note, Mark keeps eating crow with these heatwaves by underestimating them. It’s not his fault they always overperform.

    • Mike in Beavercreek says:

      I now believe we are seeing a significantly warmer planet. It is scarey although it’s a nice 54 degrees outside at 3 am in Beavercreek, Or. What a relief it is.

  12. Roland Derksen says:

    Showers are expected to move in here (Vancouver, BC) later this afternoon and evening. Not a great amount- probably less than 0.20 inches, but it’ll help dampen things down.

    • Roland Derksen says:

      Well, I sure underestimated how much rain I was going to get: The showers were slow in arriving, but once they started (a few minutes after 7pm last evening) they kept going for the next 3 hours, basically as steady precipitation. Total amount;0.42 inches, plus a few leftover showers this morning.(0.07 inches)

  13. runrain says:

    Back over 100° on Sunday??

  14. West Linn 200 says:

    Seems the word “historic” is being used quite a bit in recent years. Thankfully the fires have been kept at bay this summer (knock on wood). California hasn’t been so lucky, but that’s pretty much normal around those parts now.

  15. JERAT416 says:

    Let’s have a cold record for January

    • Bethany250ft says:

      3ft snowfall to start the month with a major arctic blast following!

      • Jim says:

        Um that would be quite devastating to a lot of people

      • JERAT416 says:

        December 2008 arctic air with an atmospheric river at the same time …..NO ice storm.

        • Bethany250ft says:

          I didn’t live here during December 2008 sadly, but it looks like the west metro had ~23″ in my area! However it also looks like there was a quarter to a half inch of ice which isn’t nice! I’m hoping the west metro doesn’t miss out next winter

    • Paul D says:

      BRING IT ON!!

      To bad it’ll never happen….

  16. OC550 says:

    Thanks for the update Mark. The cooler temps yesterday were welcomed. I’ve lived in the area all my life and only got central air conditioning a couple years ago. Didn’t feel like I needed it before, but now it’s a necessity. Watching the days get shorter as we are losing over 2 minutes of daylight each day now. I like the daylight, but it’s a sign Fall and cooler weather is coming. Still need to get through August though.

  17. Roland Derksen says:

    A warm July- no doubt about it, but not the driest in my locality. I had 1.34 inches, which is about an average amount- but 90% of that fell in the first week.

  18. Gene says:

    Another really interesting update — thanks for continuing to take the time to do these blog posts for all of us, Mark.

  19. Paul D says:

    More hot records. Wonderful….. 😦

  20. JERAT416 says:

    Thanks Mark!

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