Is Summer Getting Later? Recently, Yes!

Lows in the 30’s this morning in outlying areas sure confirm that summer is over meteorologically, although we still have some warm and dry weather ahead.  So let’s look back:

NCDC says Summer 2012 across the USA was the 3rd warmest on record, mainly due to near continuous heat in the Rockies and the extreme heat earlier in the summer in the central/eastern part of the country.

Note the cooler than average southeast and of course the cooler than average Pacific coastal areas (including us).  So ANOTHER cooler than average summer here?  Technically just barely YES west of the Cascades, but also NO.  Let’s go through a bunch of charts.  First, the warming trend in summers across the USA as a whole is pretty obvious, especially from the 70s onward:

Now take a look at just the Pacific Northwest:

Summers have generally been warming in the past 100 years, although just about all of that is post 1960. Note the big 1930s heat that brought the Dust Bowl to the central parts of the USA is mostly absent here in the Northwest.  The 20s and 30s were warmer than average, but you don’t see the huge spikes.  Those 15 years of cool summers from the early 40s to mid 50s must have been really annoying to farmers don’t you think?  Here’s something else that sticks out…there appears to be a trend downward in summer temps since around 2003.  Although we recovered to above average this year, mainly due to heat east of the Cascades when those areas were on the edge of the hot Rockies upper-level ridge.

Okay, now to just the Oregon Zone 2 chart, which is all the lower elevations of Western Oregon between the Coast Range and Cascades:

A little different, the 20s’ /30s don’t stick out as much, and a more obvious trend of warming summers from the early 70s until around 2003.  Then the same (a bit more dramatic) fall in summer temps.  Summer 2012 was warmer than the last two, but just barely made it to average.    What’s going on?  I don’t know, I’m just a short-term forecaster and big into numbers.  I do know the greenhouse I built last Fall was a great investment.

Here are two charts that seem so point to summers getting “later” across our region.  First, just August temps for the Pacific Northwest:

Wow, no downward trend!  August keeps warming up across the Pacific Northwest.  In fact this year saw one of the 3 warmest in the past 30 years!  Interesting don’t you think?  What’s most obvious to me is the disappearance of “cool Augusts”.  We haven’t seen a real cool one since 2000!  Occasional cool Augusts were the norm through the early 1990s.  I didn’t include just the Oregon Zone 2 chart for August because it’s almost exactly the same.

Now let’s put August and September together:

Looks like a trend to me.  The past 8-10 years (on average) current climate favors lots of patience for gardeners and outdoors enthusiast.  Our early summers have been unusually cool and wet (on average) and later summer/early Fall has been sunnier and warmer than average.  Will this continue the next 5-10 years?  Who knows.  And we can’t make too much out of short-term trends.   Somehow I got on a big anti-global warming email list and yesterday I saw a chart like this come across showing Pacific Northwest summer temps heading downward at “an alarming rate”.  This is what we call cherry-picking.  The graph starts in 2003.  You can compare it to the June-August NW Temp chart up above and see what they did.  They chose the hot summer of 2003 as a starting point to really make it look dramatic:

A person could have done the same thing with 1993-2003 and made it look like hellish global warming had set in.   For that matter, you could take the Aug-Sept Northwest chart and say “late summers have been cooling since 1998!”.  This is the reason I like to just present all the data and look at the interesting trends and let you make your own judgement, or maybe better to just wait 50 years and see what happens?

Chief Meteorologist Mark Nelsen

40 Responses to Is Summer Getting Later? Recently, Yes!

  1. Mr Data says:

    Thanks Mark for the number crunching even though we are only getting *half* the picture with a slant that you have to tilt your head sideways to see. *which is typical with the Liberal internet*

  2. Mr Data says:

    When the jet stream stops hugging to our north in the winter we are going to become the new Valdez Alaska once things flip the other way.

    2003 and 08 are prime examples as well as many other years we came close to being dumped with snow down here in Oregon but failed because of the jet stream not being right for us.

    The 2008 snow events we were suppose to go down to the single digits at night with snow cover and have highs of only 25F but it never panned out because of a lack of east winds.

    It’s only a matter of time and everyone who is a media whore will be caught with their pants down sadly due to the *Greenies* shutting down new energy plants we need for economy and national security reasons I won’t get into here.

    Plus having new energy plants will help encourage electric cars so we will have enough electricity to run them as they require being plugged into the main grid to be charged.

  3. Mr Data says:

    When (not if) we flip to the ice age it will start here in the NW where the Cascades will have snow later and later into the year that has a hard time going away.

    Eventually snow will not even begin to melt in the summer and our warm temps will be pushed later and later into the year until they vanish all together which all the bloggers on here will complain no doubt wondering where summer went.

    Right now we are in a sort of *in between* phase and when this drought goes away The Rockies will be slammed with snow and cold.
    The upper air data does not support global warming in any way whatsoever.

    The heat is pretty limited to the US right now which the Obama Nation Media crowd are having a field day and their party is soon to be crashed.

    About the drought.

    It is very likely there may be magnetic disturbances going on over there under the earth creating a small but permanent high pressure which won’t go away on it’s on.
    Anytime storms try to tear it apart the HP will keep coming right on back until whatever is going on under the earth settles down.

    I tried to search but cannot come up with any studies about magnetic disturbances and droughts but I wouldn’t be surprised if there is some sort of link just like some scientists believed the aurora and solar flares had a connection but nobody believed them.

    I’ve noticed over the years that when the sunspots died off like in the year 2009 The Rockies had more snow in the winter while years like this and last year the sunspots started climbing the drought increased in intensity.

    I wouldn’t be surprised to see this drought continue another winter *Unless the Semi Permanent High Pressure moves to another spot to create a drought elsewhere*

    I also believe there is a small time delay between sunspots and *Global Warming* where the atmosphere takes time to react then it comes out in full force.

    I wish I knew what the sunspot counts were for the 30s *Dust Bowl* era if they were increasing or decreasing.

  4. RobWaltemate says:

    Great charts. I aways love to have numbers to look at; too bad we don’t have number over larger time periods though. At least it isn’t just me that thinks summer feals “late” this year.

    • Mr Data says:

      I’d love to really see what happened in the 30s as that’s when we had the Tillamook Fires from ongoing drought.

      The early 40s had some pretty impressive heatwaves for Salem and Eugene with 1941 being a high of 108F in Salem and thunderstorms in Eugene that scared the living *beep* out of residents according to news archives.

  5. Ian says:

    Great stuff Mark. Sometime you should do a plot of precipitation trends over time, by month. In the Seattle area, November is getting wetter and December is getting drier, by a significant margin, in the last 60 years. I don’t know of anyone else who has looked at this, but I have to wonder if it may partly account for the decrease in Northwest glacier coverage we are seeing despite frequently healthy snowpacks and not-yet-apocalyptic summers (i.e. since rain that falls in the mountains in December is more likely to fall into an existing snowpack and stay there, than in November).

  6. Emily Waldman says:

    The east winds are sure fun up here in Longview! Warming nicely after a low of 39! BRr! I have outdoor allergies & suddenly they have gone into overdrive! I thought fires in White Salmon or Mt. Adams & the prevailing winds blowing the smoke into our area! Or the two nights of 39 degrees locally! Many of my friends locally have complained about suddenly worse allergies! Any ideas?

  7. Tyler Mode in Battle Ground says:

    East wind just picked up. and my humidity drop from 45 to 38% in one update on my weather station. Up to 74 degrees now as well.

    Now down to 33%

  8. Tyler Mode in Battle Ground says:

    At first I thought this was an error when I saw it on the Paradise weather station, however, I also found it on the Sunrise weather station.

    Notice the extreme dip in RH overnight…

    Crystal Ski Area:



  9. W7ENK says:

    Anyone going to the PDO meeting at OMSI tonight?

  10. Tyler Mode in Battle Ground says:

    A touch warmer this AM with a low of 38.

    It was a great day for a hike yesterday. Blue skies, warm temps, a nice breeze and fresh huckleberries 🙂

  11. bgb41 says:

    9/11/2012 Oregon (All) Temperature Summary

    High:89 at Brookings Airpor( 459 ft)
    Low: 60 at RED MOUND(1753 ft)

    High:45 at MT. HOWARD(7910 ft)
    Low: 20 at CABIN LAKE (4560 ft )

    Largest Diurnal Change: 55 degrees
    CABIN LAKE (75/20 ) (4560 ft )

  12. paulbeugene says:

    With the increasing warmth over the midsection of the country and Rockies during June and July, it seems to make sense that would lead to enhanced onshore flow off the Pacific Ocean, with upwelling/cold SSTs off our coast adding to the cooling.
    Later in the summer, by August and certainly by September, with lengthening nights, it inevitably should be cooling off over the Great Basin/Rockies, and I would guess that then weakens onshore flow and we get pleasant weather here.

    • Mr Data says:

      We need more smart people like you that actually studies patterns without having to throttle Global Warming down people’s throats.

  13. IceCold says:

    Are the warm east winds supposed to return on Thursday?

    I like the late summer weather….I have a few watermelons still growing, and my pumpkins are not doing so great! I think this late summer weather is going to fool us all (even Mark). I bet we get a nice winter blast similar to 2008 this Dec or Jan.

  14. bgb41 says:

    Speaking of late summers, the 18z GFS is ON FIRE!!!!

  15. Runrain says:

    These brisk westerly winds are going to play havoc with any wildfires out there.

  16. Two public Facebook notes about the same topic of warmer August-September, except my analysis focuses on The Dalles / eastern Gorge:

    It’s interesting to note that Mark’s on to the same late-peaking summer trend that I’ve noticed the past two years in particular. Of course the big question is whether this is the year the warmth continues into October or not!

  17. alohabb says:

    I would like to see how this relates to our snow fall in PDX (or lack their of) and extended cold high temps. Seems like past few years the REAL cold snowy days are late into Winter…

    • Mark Nelsen says:

      Or spring…I’ve had enough of that. Shouldn’t have to drive out for Spring Break through 5″ snow on the driveway!

    • Benjamin (West Salem) says:

      Yes, I also wonder about the snowfall trends. Here in West Salem (elevation 225′) we have had snowfall in the month of March MUCH more frequently since 2005 then I ever remember having prior to that. We used to get snow in the months of Dec, Jan and Feb, not March.

    • Mark Nelsen says:

      The first 15 years of my career here (1992-2007) I remember thinking that it just doesn’t snow in March in Portland, or that it’s extremely rare. Hopefully it’ll go right back to that soon!

    • Maybe beginning next year we’ll flip back in the opposite direction and start having lots of 60s beginning shortly after Valentine’s, and lots of trees beginning to leaf out by mid to late March!

  18. Karl Bonner says:

    The next question, obviously is WHY summer has recently been peaking later. We seem to be getting more Juneuary troughs and more Indian Summer ridges. I’m going to guess that the PDO/La Nina have an effect on the chilly Junes, but I don’t know what explains all the ridging toward the end of the summertime.

  19. Ryan (Walnut Grove) says:

    It’s seemed that seasonally we are running about a month later than usual for each season. I would guess it is a temporary shift as Brian had alluded to.

  20. bgb41 says:

    I suppose if the climate is truly warming, the characteristics of summer lag that is common on the northern california coast should become more common in the PNW. I have often thought about this being a reality but its probably just a conspiracy or just a temporary shift of the seasons. I have a feeling June/July next year will be warmer again as we wont be in a la nina phase.

  21. *BoringOregon* says:

    Yea, thanks mark great to read and learn more about the weather every week! Just went to apply for a job the winds are really picking up at least 30 to 35 mph out here. And really dry hope we don’t get a fire :/ they said it might be 39 for the low brrrr.

  22. Joshua in Lake Oswego says:

    Thanks for the information Mark! We all know that numbers don’t lie, but they can be interpreted and manipulated in a way to support a wide range of ”truths”.

  23. Thanks for the very detailed and thorough post, Mark. One can appreciate how much time you took into gathering all of this data and research.

    Now onto east wind and warmth.

  24. W7ENK says:

    Kinda what I’ve been thinking the last couple years…

    • W7ENK says:

      Mark, I’d be curious to see a chart plotting Oregon and/or PNW temperatures for June… seems like those have taken the most significant downturn as of late.

      As Rob said above, thanks for all that number crunching! 🙂

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