Weather Blog

Would 'swamp' coolers work well on hot Seattle days?

Would 'swamp' coolers work well on hot Seattle days?

As Seattle sweats through a summer that is giving signs of being among the hottest on record, those who have eschewed air conditioning (eh, it's only used 3 days a year!) or live in a place where air conditioning is not an easy option, such as high-rise condo buildings that don’t allow window units and won't work well with portable air conditioners, might now be wondering what their options are.

Some have said they tough it out with a fan in front of a bowl of ice, but that's probably getting old, especially at night as the heat stretches from days to weeks.

I've had a few people ask me if "swamp coolers" or the more technical "evaporative coolers" would work as an alternate. They're usually cheaper than an air conditioning unit, can be ordered online, and some are portable and can work in a small room, such as a bedroom, to survive the heat until September... or October. Or 2016.

But before you think, "wow, why didn't I think of this earlier?" or "why hasn't anyone else thought of this?" there's a reason: Swamp coolers aren't exactly a best fit for Seattle's climate.

Swamp coolers rely on dry air to work their magic using the same process that your body uses to cool off -- the power of evaporation. When you sweat, the process of the sweat evaporating off your skin saps heat energy from the nearby air making it cooler. A swamp cooler takes the hot air and runs it through essentially a wet cloth. As the water evaporates off the cloth, it cools the surrounding air, which the machine then blows into your room.

(Incidentally, this is also the same process of how it snows in the winter here when it's a few degrees above freezing. The rain falls from the cloud into drier air, the rain evaporates, the temperature drops, and now it's freezing and it turns to snow. And you're welcome for this trip down memory lane of what freezing temperatures feel like.)

Swamp coolers work well in the Desert Southwest, where humidity is low and the evaporative cooling process is efficient. The exception is during the monsoon season (like now) when they get tropical moisture and the humidity climbs. Then, you have to resort to traditional air conditioning or job searches that require relocation somewhere north or west.

But if you've ever gone to the southeast, you know that sweating doesn't help much. The warm and muggy air is already holding a lot of moisture, so the evaporation process is much less efficient, which is why 87 degrees in a dry San Diego feels manageable, but 87 degrees in Atlanta is like a small step above walking on glass.

So swamp coolers, ironically, are no help in the swampy air of the muggy southeast. (They really should be called "desert coolers." Or "dessert coolers" because at least for me, that garners thoughts of ice cream, and....mmmm, ice cream on a hot day....)

What about Seattle? We're on the fringe.

With our marine climate, humidity is typically higher to where evaporative cooling isn't as effective, but then again, that same marine climate keeps temperatures from really needing it in the first place.

But what about when it gets hot? Will they work then?

It depends on the type of heat wave we have.

In most summers, when it gets over 87-90, it's due to an east wind that dries out when it sinks down the western slopes of the Cascades. If you hear us talk about "thermal trough" or "heat low" or "east wind heat event", the humidity is expected to be rather low and swamp coolers would likely work. I looked up one of those such days, July 8, 2010, which had a high of 95 and a dew point of 42. Swamp coolers would have worked OK then.

But this summer, we've been hot without the drying power of an east wind, so our humidity has been higher than usual. You might have noticed it this summer, but so far we've been fortunate that while the humidity is higher, we're not to really muggy levels, save for the days when we had a chance of thunderstorms.

In doing some online research, it seems swamp coolers begin to lose effectiveness when the dew points -- the temperature at which air saturates (more information on dew points here) reach about 55-60.

With several of the hot days this summer, dew points in the Puget Sound region have ranged from about 50-58 -- it's been a bit in flux as winds are weak and variable, and some days and nights are catching a little more humid marine air than others. Wednesday was 90 degrees with a 55 dew point. Tuesday was 87 degrees with a 57 dew point. Monday night the dew points were in the upper 50s and even touching 60, which meant swamp coolers were little to no help.

And if it's too humid already, swamp coolers will have an opposite effect of not only failing to do much cooling, but will make it feel muggier. So if you miscalculate, now your home is not only warm but humid and you're likely to run straight to that store's website and give the product a 2 star review claming you ordered a swamp "cooler" not a swamp "heater" and why would someone design a product to make your house feel more like Bourbon Street?

Other nights the dew points have managed to drop to around 50, which probably would have been cool enough to work. Then again, if dew points are lower at night, it'll allow temperatures to cool a bit more at night in which case the fan in front of the window trick might work OK too.

Bottom line: Swamp coolers probably aren't the best option as they would only work well in certain heat situations. Although in those few situations, it might be worth it, but this summer, they probably wouldn't have been too much of a help so far. Traditional air conditioning is still the best option in this climate if you can find a way to swing it and if that's not an option, the fan with the ice trick just might have to do, along with a countdown clock to September 21.

June doesn’t just break, but destroys several Seattle temperature records

June doesn’t just break, but destroys several Seattle temperature records
One of many sunny and warm days in Seattle in June. (Photo: Mo Aoun Photography)

The year 1992 is remembered for a few things around here: It's when Microsoft unveiled Windows 3.1 (No more DOS!), grunge music was all the rage, the Seahawks tried their best to get the top draft pick with a 2-14 record (don't ask how it turned out)…

And it was a very toasty year, rewriting several warm weather records in Seattle.

But when the clock struck midnight Tuesday night*, almost all those records in the books got up, grabbed their stuff, and rode off into the sunset.

113 in Walla Walla? Historical E. Washington heat wave shatters records

113 in Walla Walla? Historical E. Washington heat wave shatters records

Sunday was one of those classic summer days in the Desert Southwest. The high temperature in Phoenix was 110 degrees -- four degrees above a normal day on June 28, so Sunday was a bit hot even by Arizona standards.

Still, some in Eastern Washington could have headed there to cool off as the region baked in a historical heat wave.

An incredibly hot air mass destroyed high temperature records across Eastern Washington, not only reaching unheard of levels in June, but approaching some all-time heat records as we sit still four weeks short of the statistical peak of summer heat.

Dozens of temperature records broken Saturday

Dozens of temperature records broken Saturday
June 27, 2015. Seattle, Wash. KOMO PHOTOS

The heat wave Saturday wasn't just impressive for the actual temperature readings, but for the time of year. Some of the temperature readings observed across the Pacific Northwest are usually reserved for the peak heat of the summer.

Some spots in Oregon and southeastern Washington broke not just daily temperature records, but all-time June records!

Here are a list of record reports from the various offices of the National Weather Service:

What causes those 'Jellyfish' type clouds spotted over the South Sound?

What causes those 'Jellyfish' type clouds spotted over the South Sound?
Photo courtesy: Kelsey Holloway from near Olympia on June 26, 2015.

The sight is a bit surreal -- floating clouds that look a bit like jellyfish floating in the skies over the South Sound. An alien species?

No, something much more mundane -- just regular atmospheric physics at work.

Why you can escape this weekend's heat, but not next weekend's

Why you can escape this weekend's heat, but not next weekend's

Seattle is set to reach the 90s this weekend, but there is relief to be found by making a jaunt to the coast where it's expected to stay in the 70s, or far North Sound where it'll stay in the low 80s. It'll be spread of temperatures similar to the last time Seattle reached the upper 80s in early June.

But a second heat event scheduled for the end of next week into the following weekend also has Seattle set to reach the 90s, only this time, there will be no escape. Even the coast will bake in the upper 80s and 90s.

How does the coast get off scot free in one heat event but not the other? It's all on the wind, or lack thereof.

Northern Lights make for brilliant show over Pacific Northwest

Northern Lights make for brilliant show over Pacific Northwest
Photo: Holly Davison Photography

Northern Lights possible Monday night, and other weather tidbits

Northern Lights possible Monday night, and other weather tidbits
Northern Lights come out early on the morning of June 23, 2015. (Photo courtesy: AlpineMike's Outdoor Photography.

UPDATE! The Northern Lights did come out Monday night!!! Here is my blog with the budding gallery of photos - incliding the one above taken by AlpineMike's Outdoor Photography. Thanks so much to all who stayed up so late to get photos!

A sunny and 76 degree day around Seattle might seem rather mundane, but we actually have quite a bit going on in the weather department that is worth noting.

Probably the most exciting is a strong geomagnetic storm that is in progress Monday and holds promise to last through Monday night -- at least long enough to get it dark around here.

8 days of 90s in Seattle in 2 weeks?!? Why 15-day forecasts don't work

8 days of 90s in Seattle in 2 weeks?!? Why 15-day forecasts don't work
Sun sets in Seattle on June 19, 2015. Photo by Mark Ashmun.

You can give them an A for effort, but a C- in execution…

While weather forecasting technology has made several important advancements over the past few years, the ability to get a good, consistently accurate forecast beyond 7 days still remains rather elusive.

A few time lapse videos that will knock your socks off

Photographers have been busy getting some great shots of Mother Nature lately, both locally and around the globe.

Let's start locally -- I'm sure many of you saw the incredible sunset Wednesday night. Well, Michael Reid did the photos one better by capturing a time lapse video of the sunset from his perch high atop the Columbia Center (video above).

Seattle warm stretch to last into September ... 2016?!?

Seattle warm stretch to last into September ... 2016?!?
Sun rises over Seattle on June 16, 2015. (Photo: Meg McDonald.)

It's the third Thursday of the month, or as Seattle meteorologists are starting to know it as: "The day the new long range maps come out and say the same thing as last month's did."

Yes, it's time for the update to the monthly 30- and 90-day seasonal outlooks, and yes, it's pretty much the same as June's. And May's. And April's. And... you get the picture. At least for the temperature part.

Shifting winds to present extra challenge to U.S. Open golfers

Shifting winds to present extra challenge to U.S. Open golfers
Beau Hossler, amateur, watches his tee shot on the ninth hole during a practice round for the U.S. Open golf tournament at Chambers Bay on Wednesday, June 17, 2015 in University Place, Wash. (AP Photo/Matt York)

The entire focus of the golfing world will be on the Puget Sound region this week, with the U.S. Open taking place at University Place's Chambers Bay golf course from Thursday through Sunday.

While the beauty of the region will certainly be a topic of discussion during the broadcasts, I'm sure our rather soggy/cool reputation will come up once or thrice as well.

But while you might think rain would be the biggest challenge golfers might have assumed when they started plotting their strategy of playing a Pacific Northwest course (and it will, at least a little bit) it turns out it's the wind that could have a far greater effect on their scores.

Some of the golfers have already experienced the fickle Puget Sound weather in the practice rounds this week.

When is a rainbow a 'sun dog' and when is it a 'halo'?

When is a rainbow a 'sun dog' and when is it a 'halo'?
Photo of a sun dog spotted over the Olympic Mountains, taken by Tim Durkan on June 16, 2015.

Tuesday was quite the weather variety show, with cirrus clouds floating around creating several different but colorful effects in the sky.

The sights were all in the same realm -- a small rainbow floating in the sky with nary a rain shower to be found - but they have different names depending on how they were created.

'Fire Rainbows' dot the skies over Puget Sound region

'Fire Rainbows' dot the skies over Puget Sound region
Photo courtesy: Jen Brazas

The thin, wispy clouds floating around the Puget Sound region Monday usually do nothing more than give the blue skies a little bit of character.

But today, they were giving the skies a little bit of color.