Heading Toward A “Warm Nights” Record; Warming Summers Too

BMAC 60 Degree Nights

The 61 degree low at PDX this morning was the 43rd morning this warm season when the temperature didn’t drop below 60 degrees.  The all-time record of 44 days was set just last summer.  If we have two more 60 degree mornings, we’ll set a new record.

It is important to point out that technically the low temperature records are for the calendar day…from midnight to midnight. For example, if it’s 62 in the morning, but then that evening cooler air pushes in with a 58 at 11:59pm, the low for the day is the 58 and it wouldn’t count in the graphic above.

And yes, Portland metro area nights are getting warmer and warmer aren’t they?  Here’s an updated look at 60 degree nights at PDX over the past 70+ years


Much of this is due to the Urban Heat Island effect…as cities grow they turn warmer.

But are our summers getting warmer? The short answer is YES.

To eliminate most of the urban heat island effects, you can average all stations in NCDC Climate Division 2 in Oregon.  That’s the Willamette Valley (and foothills) stations.  There’s a slow warming since 1950 during the 3 month period June-August. jun-augdiv2temp

Note that from the late 60s to early 80s there was a flattening or even cooling trend in there.

As I noted a year or two ago in this blog, the July-September warming is more significant (summers are hanging on longer?). In fact the only significant change in temperature in the lowlands for the past 30 years has been a cooling in the late spring and warming in the late summer.  Here is the spring chart


and the July-September chart


Winter and fall haven’t seen much of any change. In fact I noticed the Cascades have seen just about NO change in the winter months.  Keep all these numbers in mind when people argue with you one way or another over Global Warming.  Not quite as clear-cut as some would have you believe!

Chief Meteorologist Mark Nelsen

30 Responses to Heading Toward A “Warm Nights” Record; Warming Summers Too

    • Mark Nelsen says:

      That doesn’t surprise me, it’s such a small warming so far that it could easily be natural variability here.

    • Jesse-Stevenson says:

      Agreed. We are in a fairly unique position on this planet being directly downstream from its largest body of water. Makes sense that it would have more say in our overall weather than emissions, at least for the time being.

      I’m curious what shifts in wind patterns they are talking about though. Wish they would have elaborated a bit more.

  1. Garron near Washington Square says:

    Mark, along the lines of your blog, Cliff Mass’s current topic suggests this will be an average summer by around 2050 for the PNW. My question is which way precipitation will trend? My guess is slightly more precip, with higher freezing levels in the winter.


  2. W7ENK says:

    252 PM PDT MON SEP 22 2014

  3. W7ENK says:

    After tomorrow, my bike commute to work and back is going to suck.

    Gotta maintain my 100%!

  4. WEATHERDAN says:

    69 and mostly cloudy in Salem at Noon. Maybe .33 to .50 rainfall headed our way Wednesday and Thursday. Then a warming and drying trend headed into the weekend. Maybe close to 80 by next Monday. Still very warm last night. Dropped down to 57 degrees. Probably another record warm month mainly because of the very warm nights. Peace.

  5. schmit44 says:

    9/21/2014 Oregon (All) Temperature Summary

    High:94 at PINEGROVE( 620 ft) & EW1735 Central P(1285 ft) & WARM SPRINGS BAS(1563 ft) & DW9562 Wolf Cr.(1470 ft) & PROVOLT SEED ORC(1180 ft) & EW1140 Umatilla(364 ft) & UNION(2708 ft) & EDEN(4200 ft) & GRANDE RONDE RIV(1594 ft) & Medford, Rogue V(1329 ft)
    Low: 68 at DW7303 Ashland(2257 ft) & WYETH(102 ft)

    High:59 at EW4856 Brookings(1365 ft) & Garibaldi(0 ft)
    Low: 34 at CRANE PRAIRIE (5500 ft )

    Largest Diurnal Change: 52 degrees
    PRAWS 7 (RED’S H (91/39 ) (3618 ft )

    Heaviest Rainfall:
    0.09″ at DW4535 Cannon Be(23ft)

  6. High Desert Mat says:

    Ya, I can see it to my west. Been going for a few hours now. But nothing overhead. Warm night foe sure relatively. 73 now and has been warm/hot all day. Coming to an end though soon according to models. Euro has highs for me of only 67 by Thursday

  7. Boydo3 N. Albany says:

    Took a walk around the block and low and behold!! Ligntning to the east! Looks like just to the east of Sweet Home along the crest of the Cascades.

    • Benjamin (West Salem) says:

      I love little surprises like that. I see that the area Forecast Discussion mentioned the slight chance of something popping up over here west of the Cascades. I also have to wonder if there will be convection with the front on Wednesday. It looks fairly strong for this time of year.

  8. schmit44 says:

    9/20/2014 Oregon (All) Temperature Summary

    High:101 at DW5789 Eagle Poi(1463 ft) & EW1735 Central P(1285 ft) & MERLIN SEED ORCH(1144 ft)
    Low: 66 at CW2654 Corbett(1050 ft)

    High:60 at Newport(30 ft)
    Low: 32 at Horse Ridge (US (4160 ft ) & KIRK (4519 ft ) & DIMLKE (4726 ft ) & CRANE PRAIRIE (5500 ft )

    Largest Diurnal Change: 53 degrees
    Beatty (88/35 ) (4320 ft )
    KLAMATH NWR (87/34) (4531 ft)
    Cresent (US 97 M (86/33) (4455 ft)

  9. 81° at 11pm this evening here. Not bad for late September.

  10. dharmabum says:

    97 degrees here at Barton with 11 % humidity and a lot of smoke in the sky from the 36 pit fire. Sure hope they have a good handle on it with the east winds picking up also.

  11. schmit44 says:

    9/19/2014 Oregon (All) Temperature Summary

    High:92 at Brookings (US 10( 150 ft) & CW6811 Grants Pa(947 ft)
    Low: 67 at ROWENA(116 ft) & WYETH(102 ft)

    High:54 at MT. HOWARD(7910 ft)
    Low: 28 at KIRK (4519 ft )

    Largest Diurnal Change: 49 degrees
    Sand Creek (US 9 (79/30 ) (4525 ft )

    Heaviest Rainfall:
    0.21″ at North Bend Munic(16ft)
    0.11″ at Sexton Summit(3837ft)

  12. Jason Hougak says:

    NWS shows snow level down to 7500′ next Friday. Hoods looking a bit naked and need his white tuxedo back!

  13. WEATHERDAN says:

    Time for an almost final wrap up of weather this Summer in Salem. Location: South Salem. Equipment: Oregon Scientific basic weather station. Time reference. 2014 inclusive except for low minimum which is June-September. Absolute Maximum 101.3 on July 1st. Absolute minimum 43.1 on June 6th. Precipitation June 1st-September 19th 1.41. Total days 100+ 1. Total days 90+ 34. Total days 80+ 85. Total days 70+ 130. Total days minimum 60+ 32. May Avg. 72.7/48.6=60.7 June 75.2/51.7=63.5 July 87,7/60.5=74.1 August 87.0/59.1=73.1 September 1-19 83.7/51.7=67.7 What a Summer it has been and it’s not over just yet. New models trending drier and warmer than yesterday so while we get some rain next week I feel this is not the end of our warm Summer weather. Typically that happens around mid October. As far as the 90,s go this week end is probably it, but we could still get more 80,s. At 1:00 PM Salem is sunny and 79 degrees. Peace.

  14. JLA says:

    It’s the Warm Blob!

  15. PurpleHaze says:

    For Salem it’s hard to believe today’s record low is a bone chilling 34F degrees in 1928! Talk about a touch of frost as that’s the air temp not the ground temp!

    Can something like that happen today or has UHI ruined it? Or is it a result of simply poor pattern development?

    • paulbeugene says:

      It was 31F at Eugene airport 9/23/2000, very much in the modern era, coldest ever at that location in September.

      Coldest it got in September at the old Eugene station was 30F in 1926 (sep 24).

      Radiational cooling happens.

  16. dharmabum says:

    Smoke from the 36 pit fire really moved in here around Barton Park area for the first time in a week, really socked in. Also just to comment that a better description of “global warming” is Climate Change, which better describes manmade impact on our climate.

    • Mark Nelsen says:

      But the changes in climate are produced by a warming planetary atmosphere/ocean, so it’s global warming to start with.

    • dharmabum says:

      Interesting Mark that tonight on the KGW Ch. 8 Straight-talk show where the subject was forest fires with reps from the U.S. Forest Service, the State Forestry Dept and respected KGW Channel 8 meteorologist Matt Zaffino. Where Matt in his segment referred to Climate Change exclusively in his dialog and graphics.

  17. pappoose in scappoose says:

    Visibility zero and I can’t see anything either!

    “the brilliant sun glare may be preventing you from seeing the cliff we’re about to fall off.”


  18. gidrons says:

    At my location at 1000′, I give this summer an “A”. I

  19. schmit44 says:

    9/19/2014 Oregon (All) Temperature Summary

    High:90 at NELSON(2567 ft) & Weatherby Rest A(2390 ft) & ALKALI FLAT(2495 ft)
    Low: 69 at BLALOK(277 ft)

    High:52 at Timberline Lodge(7001 ft)
    Low: 38 at CW9027 Ukiah (3415 ft )

    Largest Diurnal Change: 36 degrees
    EW2055 Prairie C (79/43 ) (3547 ft )

    Heaviest Rainfall:
    0.91″ at EW4856 Brookings(1365ft)
    0.89″ at RED MOUND(1753ft)
    0.82″ at AGNESS2(247ft)
    0.64″ at FLYNN PRAIRIE(1543ft)

  20. Is there a publicly-accessible link to where you can tinker around and make seasonal climatology charts like this, Mark?

  21. Boydo3 N. Albany says:

    This must be why my garden maxed out so early this summer and now is going for round 2. Doubt round 2 is gonna make it 🙂

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