July 31, 2013

The Best July Weather in Generations for the Northwest?

July 2013 was probably the best Northwest weather in a half-century or more.  Perfect temperatures west of the Cascade crest, lack of rain, plenty of sun...this month had it all.

And we broke or tied some amazing records this month:  be prepared to be impressed.   I had to wait until this evening to be sure about several of these records, as a band of convective showers moved northward across the region during the afternoon and early evening hours.  But now the story is clear.

Perhaps the most extraordinary occurrence was the aridity of the northern Washington coast.   Quillayute (near Forks) tied the driest month on record set 124 years ago in 1889 (.01 inch).     The precipitation record I am referring to actually combines two stations because of a move.  From 1883-1966, the station was at Tatoosh Island and from 1966 on a Quillayute.    This is a very big record to tie.  No one alive today has experienced such dry conditions on the coast.

What about Seattle?  The airport only had a trace of rain, the driest since 1960.   There are plenty more of these, but you get the point.

To get some perspective on this, here is a map (from the Western Region Climate Center) showing the percentage of normal precipitation for July 1-30, 2013.   The Northwest was VERY dry, with the coastal region experienced 2% or less of normal.
Ironically, it has been far wetter than normal in Arizona, New Mexico and much of Nevada!

But what about July  temperature?   How many ways can you say perfection?  Let's start with Seattle-Tacoma Airport.  In the figure below the red line is the average high and blue line is the average low.  Only about a handful of days were below normal and only two days failed to reach 70F.   No days in the 90s.
Pasco and Spokane?  Same story, but add 10-15F.  Warmer than normal with very little cool weather (see graphics).  Obviously, the drought and warmth east of the Cascades has a down side, with a substantial fire threat (essentially we had mid to late August ground/fuel moisture in late July).
 A more comprehensive view of the temperatures are found in the difference of the monthly average temperatures (through July 30) with normal conditions (climatology)--see graphic. West of the Cascade crest the temperatures were near normal (i.e., near perfect), but warmer than normal conditions were found to the east. Southeast Oregon was very hot (and dry).

I have looked through the Sea-Tac records of the past few decades and could find no July  as comfortable as July 2013.   This is surely the best July on record for most of you.

We have a few days of cooler than normal temperatures and a higher chance of precipitation ahead of us because of an upper level trough (particularly wet  over eastern WA and the northwestern corner of the State).   But it should warm up later in the weekend.  Here is the latest Climate Prediction Center 6-10 day forecast.   Above normal temperatures over our region and below normal precipitation over the western side.

Enjoy.  You will be telling your grandchildren about this July one day.


  1. Is Seattle weather the same as Northwest weather? While Seattle may have had consistent temperatures in the 70s, much of the gorge and eastern Oregon and Washington had consistent temperatures in the 90s and 100s. Is this nice weather? Are these places still in the Northwest?

    Also, why is dry weather the "best" weather? Much of the forest and natural vegetation is heat and water stressed. There is fire, smoke, and extreme fire risk in much of WA and OR.

  2. It has been wonderfully cool with low dewpoints here in the midwest. If you want this ridge, we'll take the trough!

  3. Having lived in the Puget Sound region for over 60 years I have to agree with you. This was a July like none that I can recall. Perfection indeed. I just hope the memories get me through next winter.

  4. You bet, Cliff. And it was a gorgeous July following a great June. All I have to do is look at my corn and tomatoes, they tell the story...

  5. Assigning subjective human values to weather phenomena is unscientific and makes folks like me feel bad.

    I am a fair skinned man who has spent years making a living outdoors. Sunny and 80 degrees is a receipt for a very uncomfortable day for me. A perfect day for me is 50 degrees with an occasional rain shower.

    I know

  6. I live in the Northwest for the rain and cloudy weather! I often resent the correlation between sunny dry weather and the word "good".
    Personally, I never ever complain about the rain, but do absolutely hate this bright and hot weather.

    If things continue to warm up, I may be looking to relocate somewhere with cooler and wetter weather patterns.

    I keep awaiting the Cliff Mass blog update predicting cooler temperatures and rain. Every summer day is one day closer to autumn.

  7. Your definition of perfect temperatures is different than mine. Way too cold and cloudy this summer. If I tell my grandkids about this July it will be to say that this was the year that everybody went around Seattle popping their wads about what an amazing summer it was, apparently still failing to realize that every other place in the country gets the exact same weather and just calls it late spring and/or early summer.

  8. I agree with the folks who say hot, dry weather isn't great weather.
    Drought, water-stress, wilting vegetation - none of these seem good to me.

  9. "apparently still failing to realize that every other place in the country gets the exact same weather and just calls it late spring and/or early summer. "
    The difference being that those other people enjoy their spring and early summer knowing that July and August will bring unbearable heat and humidity.
    I've found this month to be perfectly lovely...easy to plan outdoor activities without worry about rain-outs. Sorry for the minority who haven't enjoyed it, but we all get our turn with weather that we don't like eventually.

  10. I hear a lot of people talking about "getting away" during the summer,and I think, "Why?!

    I've never enjoyed my back deck as much as I have this summer. Shade, perfect temps, a light breeze out of the North.


  11. Wow, what a number of unhappy campers on this particular blog.

    Cliff, as usual you are right-on with the data to prove it. If anyone did not like this July you should seriously think of moving somewhere else...looking forward to August!

  12. A hot day on the East Coast usually includes humidity and a whiff of disgusting air pollution. All hail the NW!

  13. Yes, a ton of whiners. There will always be exceptions to every rule. Just because you may be one of those doesn't negate that the *majority* of people think this summer has seen some of the best weather ever in the Puget Sound. Yeah, yeah, I get it... you like the rain, you like the clouds, you like it 50 degrees. Don't worry... you'll get that soon enough. For the rest of us, this respite is godly.


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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