Friday, it was sort of Phoenix-like, with highs in the upper 90s and low 100s across the Puget Sound area (Seattle hit 97, while Olympia hit 101.)

Saturday, it was more like Atlanta, with highs still in the 90s, but much higher humidity to deal with. In fact, this exact pattern we were in Saturday is the one and only pattern that can make it hot and muggy around here at the same time.

So even though Saturday's highs were a couple of degrees cooler than Friday's in many places (96 for Seattle -- which still broke the record high for the day), it felt hotter than Friday.

Here's how our heat wave has stacked up so far:

How Did It Get So Humid?

As we mentioned, there is only one weather pattern that can make it warm and muggy here, and this is it. Most of the time, our air flow comes from the west or southwest, so it's coming off the cool Pacific Ocean, keeping temperatures down.

On hot days, the flow usually comes form the east/northeast. That area to our east is pretty dry to begin with, but as air comes down the Cascades, it sinks, compresses, and gets even drier. That's why almost all our heat waves are a dry desert-like heat.

But, we do have one Achilles Heel, and that's to our south. On rare occasions, some tropical/monsoonal moisture from the Desert Southwest moves up due north along the West Coast. In this case, it's not going over the ocean, so it's not getting any cooler, but it's also not coming from the east, so we don't get the drying effect off the Cascades. And since the land to our due south is relatively flat, the humidity holds.

Thus, you get a day like Saturday. Happens maybe once or twice a year, but it's typically not this hot when it does so. This is just bad timing with a hot air mass already in place.

Why Does Humidity Make It Feel Hotter?

The reason humidity makes it feel hotter is it makes it harder for your body to radiate heat. The body cools by sweating, which then evaporates into the air. The warmer molecules in those sweat droplets evaporate first, leaving the cooler ones behind and, in turn, make you feel cooler.

If there is more moisture in the air, it's harder for water to evaporate, so it's harder to cool off, thus making you feel hotter.

How Hot Is It Now?

Check this image below for the latest current temperature, updated once an hour at roughly 10 minutes past:

If you don't see your city listed, you can try this link as well. This link will also show you the relative humidity, if you're so inclined to find out just how humid it is.

When Does This Heat Wave End?

Believe it or not, the heat wave is not done yet. But we do have a little good news.

The clouds and monsoonal moisture are clearing off to the east, allowing drier air to return. That should at least drop the humidities back some and get rid of the muggy feel later tonight and into Sunday. Saturday night lows will still be very warm -- in the mid-upper 60s.

So, Sunday is back to sunny and hot Phoenix-like weather once again. Highs should once again reach the low-mid 90s. The record high for Seattle is 99, so that should be safe. There is, however, still the risk of a shower and/or thunderstorm forming over the north Cascades and then drifting west over the lowlands. We'll see how that pans out Sunday morning.

If this hot is getting to you, you can try the coast on Sunday, which should finally cool off back to around 80.

By Monday, we should finally -- finally! -- be getting rid of the main heat-wave maker and perhaps start to get our marine breeze back. Temperatures should drop to the low 80s on Monday, and then gradually back to the 70s by the end of the week, finally getting us back home to more Seattle-like summer weather. :)

For More Information:

If you were looking for some of the stuff in Friday's weather article (records, staying cool tips), here's the link: July 20th story from KOMOtv.com