July 27, 2021

The Most Perfect Weather Month in Western Washington History

One can make a pretty compelling argument that July 2021 will go down in the record books as the most perfect weather month in western Washington history.

Perfect in every way

Moderate, but warm temperatures.  Cool enough at night for sleep.  Lots of sun. No wildfire smoke.  Good air quality.  No rain.

Picture today over Puget Sound, courtesy of Ben Slivka


Consider Boeing Field in Seattle.  Every day has had maximum temperatures between 69 and 84F.    Never too cool or too hot! And enough variation to keep it interesting.  But wonderful for outdoor recreation.

Cool enough to sleep at night?  You bet!   

Every day at Boeing Field had low temperatures below 65F and most days dropped to around 60F or the upper 50s.  And that is in the middle of the urban heat island.  Most folks enjoyed even cooler nighttime minimum.    You could sleep well without AC!

What about sticky conditions?  Humidity that can make life so unpleasant in much of the U.S.?

Not here in western Washington!  A very good measure of unpleasantly "sticky" conditions is when the dew point gets above 63-65F.    Remember that the dew point is the temperature at which the relative humidity gets to 100% when the air is cooled.   

Look at the dew point this month at SeaTac Airport (below).  Never above 59F and for much of the month it has been less than 55F.   No wonder it has felt so comfortable!

What about wind?   A little wind is a good thing, making conditions more pleasant.  And as shown by the winds at the UW Atmospheric Sciences Building, most days had just around the right amount, with sustained winds during the afternoon getting up to around 12 knots...and sometimes a bit more.

Many afternoons have brought a highly pleasant Sound Breeze to Puget Sound, with excellent conditions for those with sailboats.  Just ideal

Sunshine?   Most days were at nearly full sun, which means few clouds and NO SMOKE (see solar radiation at Seattle below).

And let's talk about smoke, which is both depressing when it hazes the sky and which is unhealthy when it reaches the surface.

Basically, western Washington has escaped smoke this summer as onshore, westerly flow has pushed any smoke away from western Washington.   A visible satellite image from yesterday illustrates this smoke-free boon:

Air quality at the surface has been excellent in July around western Washington, as illustrated by today's evaluation by the excellent Puget Sound Clean Air Agency (see below).

But what about Tacoma?  Low particulate levels (under 15 micrograms per cubic meter), except for the July 4th fireworks.   Excellent air quality.  No smoke.

 Finally, what about rain, which can dampen outdoor activities and ruin that trip to the mountains.  

Little rain...just a few hundredths in the interior and a quarter inch on the coast.  Much drier than normal.  The monthly totals are below (click to expand).

 I have gone back many decades into the meteorological records of the region and no July or ANY OTHER MONTH has offered such consistent meteorological perfection.

But Some Have Another View

Now in the current psychological state of the world, the media, social media, and politicians are totally obsessed with the negative, particularly in environmental matters.

During the last month, major media has been obsessed with meteorological disasters from floods and heatwaves to wildfire smoke and drought...to name only a few.  Just one front-page disaster after another.

So where are the banner headlines about our wonderful weather:  the envy of the world?  

In fact, the Seattle Times, with a tendency for apocalyptic (and generally ill-founded) global warming stories, had a front-page story about THE BIG DARK.   About how miserable we will all be in the upcoming period of darkness.  I thought it was a Seattle Times joke when I first saw it, but they were serious (see sample below).  All in the middle of meteorological nirvana.

Western Washington generally has the best summer's in the nation and this month was off the charts wonderful.   Time to recognize it.


  1. Oh, Cliff, that hurts. . . .
    I'm happy that weather has been good in the Sound, but here in the Methow July has been a challenge. Heat, wind, smoke.

    1. Steve...sorry. The Methow Valley has certainly experienced a lot of smoke from the nearby fires. If you need a break, come visit the west side. The eastside forecast are not in good shape and we need to thin them and do much more prescribed burning..cliff

    2. Cliff, what about the designated Wilderness areas which are essentially "no interference" zones? I am somewhat skeptical that we can solve the wildfire crisis with prescribed burns. Perhaps (I hope) that things will settle down into a "new normal" as the average temperature increases. I love the sunshine but after a few weeks of straight sunshine fires start breaking out if there is no rain. A week of rain in August used to be traditional.

    3. Miserable AQI currently in the Methow (Mazama 528 on PA) and it looks like it's going to stay that way for the next 10 days. And the fall is when we typically get inversions and really stagnant air. Yikes.

      You're right Cliff, the surrounding forests needed to be cleaned up by fire, unfortunately bad air is the price we pay. It's now virtually a big prescribed burn.

    4. Ansel, designated Wilderness is not off limits to fire suppression. However, resources are limited and best directed to areas in close proximity to human residences. Wildfire is also an ecologically necessary phenomenon that should be allowed to seasonally run its course away from communities. Prescribed burning does have limited benefits near population centers, thinning much less so despite what Hilary Franz might say. Consider that the Cedar Creek fire near Winthrop is running hot through recently logged DNR land, and that our largest state fire in 2020 tore through steppe with small, isolated stands of trees.

  2. Banner month. Thanks for the write up.

  3. I was born here 65 years ago and though I do appreciate the consistently cooler nights, I miss the bits of rain we usually get in July. Then again, when it finally arrives, there will be epic petrichor.

    1. Petrichor. I learned a new and very useful word. I've wondered if there was a word for that wonderful smell of finally wet earth. Thank you.

      I, too, miss the lovely July rains. I hope August brings some much needed moisture. My garden is lusting for an "epic petrichor."

  4. Really enjoyable weather - but a couple of weeks ago we had daily fog here in Anacortes. Not unpleasant, but we couldn't exactly show off our perfect weather to family visiting that week from Southern California.

  5. Any thoughts on the next couple of weeks as we transition into August? Traditionally a SeaFair weekend or two, historically also good weather. Will the rain and smoke continue to hold off?

  6. Context matters. Maybe there would be more rejoicing in the so-called "perfect" July weather if it hadn't been preceded by June's massive heat dome. All the singed foliage and stressed trees dropping leaves like it's already fall - it's disheartening. People understand that the vegetation around here needs more than just sunshine and cool breezes. Then there's the millions (billions?) of sea creatures that were killed by the heat along the coast. Who knows yet the extent of the repercussions from that catastrophe. And as another reader already mentioned, our neighbors to the east and south are suffering with continued extreme heat, fire, and smoke. The fact that peoples' outdoor plans weren't disrupted by a rain day for an entire month seems pretty trivial by comparison.

    1. Unknown.... western WA is not in drought. Our water year precip was near normal. Our snowpack this year was above normal. The loss of some shellfish was mainly the result of extreme low tide during the middle of the summer. Our reservoirs are in good shape. So the context is generally good, bot bad...cliff mass

    2. I agree completely with your dire and apocalyptic scenario. Care to join me in a suicide pact, kid? You first...out of respect, of course.

    3. So you're so far gone that you can't even bear to recognize a great month. Why? Are we obligated to be as terrified as you are?

    4. Totally agree with anonymous assessment that the weather is far from perfect in such a prolonged bout of hot temperatures and lack of rain. It was from Cliff Mass that I learned the oft repeated line that summer in the Northwest statistically begins about July 12th. We have never had to water so much, so early in the year to keep our pkants alive. I don't recall the necessity of a statewide fire ban so early. It ain't all doom and gloom but living so close to the forest with dead leaves already crunching under foot doesn't make me happy, it makes me nervous.

    5. Last September I experienced two massive fires that came within 5 miles of my home...and I live right at the southern border of the city limits of Portland. Had a level 2 evacuation order for almost a week, after the firefighters gave up containment efforts because of imminent danger from the uncontrolled flames. Given all that, I still will never have an outlook as dire as yours.

    6. Eric Blair - got a flair for the dramatic eh? someone offers an opposing viewpoint and you suggest suicide? wow.

      Unknown 2 - Who said anything about being terrified? Just pointing out readily observable facts - singed foliage, trees dropping leaves in July, marine animals killed by the extended period of extreme heat (according to University of British Columbia marine biologist Christopher Harley). Also 'great' and 'perfect' are matters of opinion. Are we obligated to like an entire month without measurable precipitation just because you do?

      Unknown 3 - Yep. Early fire bans & firework restrictions. Lots of supplemental watering. Living with a very dry green space nearby with some trees that are almost completely defoliated. Makes me a little nervous as well because there's always someone can't follow safety recommendations. Hopefully no gender reveal pyrotechnics happen before the rain returns. ;)

  7. I'll take 'the big DARK' any day, any time, ever and always over drought and wildfire smoke.

  8. I've been nearly stunned by this incredible fortune of sunshine and lovely warmth in our area! I'm dizzy with delight!

  9. I call this type of weather Santa Barbara weather, because they have consistently good weather year 'round. Well, usually.
    I've been making up for lost time in July with that deferred maintenance around the house. Pressure washing, painting, gardening. It's been terrific.

  10. Thanks for the positivity Cliff. It's a rare thing these days.

  11. The temps have been great, but I wouldn't use the word "perfect" without some nice doses of rain mixed in. It's WAY too dry out there, and I'm worried because there is the potential to not see rain again until September. Living in a town surrounded by tinder-dry forest is a little concerning. This farmer is not too hot, but definitely water stressed out!!!

  12. I agree with Benjamin above. The weather has been recreationally perfect, sure, but I’m a farmer, and trust me when I say we need the rain. The heat dome wiped out or made very short seasons for our spring crops, and no rain means extra irrigation for farmers fortunate enough to have water rights and the infrastructure to water. Farmers without are out of luck. It’s been a tough season.

  13. It is unusual to hear a farmer that does not complain about the weather. I guess I'm a farmer too, a small woodlot owner with a little more than 50 acres of timber in the foothills of the coast range in western Oregon. We did have 2 very hot days in June (106F at my house), but in my case it didn't have a major impact on soil moisture. The young trees are growing like gangbusters, on track to make 3 - 5 feet this year (I know that sounds like an exaggeration, but I measured them). Unfortunately, the invasive species are also having a great year. Oh well.

  14. One rainy day a month during a work day would still be perfection. Just enough to put the water hose and the sprinklers away for a bit. In addition to keeping the highway medians a bit greener....and not on fire. Having a camp fire while in the mountains would be a nice, nostalgic addition as well, that the dry conditions has currently pumped the brakes on. Moderation and variety is good too.

  15. Having hiked in the mountains here for 30 years now, while it is perfect hiking weather - I always time a backpacking trip for July 25th - it's also insanely dry. Except for the past few years, there has always been residual snowpack well in August - this year there is absolutely nothing up there. In the 90's it was common to time trips to the Goat Rocks for late August - no guarantee until then that the snow would be gone and flowers out. So - perfect weather, no smoke - but it's really, really, really dry.

  16. I wonder if all the dead salmon and shellfish agree that the weather is as spectacular.

  17. That glass of whiskey looks mighty weak for celebrating the recent weather.. :^p

  18. How come an article from CNN comments on the greatest mass balance loss of the year for Greenland but I don't think it comments on how the surface mass balance of Greenland this year is above the 1981-2010 average?

  19. Go to Weather Underground. Pull up station KWAKENT109. That's about five houses over from me.

    It's 92 degrees, as I write.

    It's not the first time this month, either.

    I get the argument that global climate change is responsible for no more than two degrees. I understand that you feel a civic duty to get that argument out there.

    But this month has been stiflingly hot. Any temperatures over 80 are too hot.

    To present this as "perfect" is just defining deviance downwards, to use a fine 1970s phrase. (Or upwards, I suppose.)

  20. Things are not so sanguine with NOAA:
    "Pacific Northwest Drought Update
    July 29, 2021
    Drought Status Update for the Pacific Northwest

    Summer Heat Worsens in the
    Pacific Northwest

    This Drought Status Update is issued in partnership between the states of Oregon, Washington, and Idaho, the USDA Northwest Climate Hub, and the Natural Resources Conservation Service to communicate a potential area of concern for drought expansion and/or development within the Pacific Northwest based on recent conditions and the upcoming forecast. NIDIS and its partners will issue future Drought Status Updates as conditions evolve.

    Key Points

    · The drought in the Pacific Northwest in 2021 can best be described as a spring drought. The Pacific Northwest has not seen this dry of a spring since 1924 and this is the 2nd driest March-June for Washington, Oregon, and Idaho on record (period of record 1895-present).

    · The failure of springtime precipitation to bolster high-elevation snowpack and supplement snowmelt runoff has left the region facing an early fire season with extremely dry conditions, low base flows early in the summer, and reservoirs that are quickly being drained to meet water demands that are higher than normal because of the severe early and mid-summer heat waves.

    · The exceptional precipitation deficits across the Northwest can be illustrated by the record low precipitation from March 1 to July 25 at approximately 90% of SNOTEL sites.

    · 93.22% of the Pacific Northwest DEWS region is in drought, with 55.06% experiencing Extreme (D3) or Exceptional (D4) Drought conditions.

    · Drought is exacerbating wildfire risk, with numerous large wildland fires burning across the region.

    · Preliminary mortality data from the Washington Department of Health indicate 117 people died of heat related deaths during the late July heatwave, with the Oregon Health Authority reporting 116.
    · Twenty-two counties in Oregon have drought declarations. Nineteen counties in Idaho have drought emergency declarations. On July 14, 2021, the Washington Department of Ecology issued a “Drought Emergency”

  21. Definitions of drought vary from agency to agency and group to group. One can now declare whatever they feel like.


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

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