Portland In October: “Like A City In The Desert Southwest”

Here’s a crazy one.

On the afternoon of Friday October 5, 2012–Portland’s air was almost exactly as dry the air in Phoenix, Arizona and Las Vegas, Nevada!

You can see the comparison of relative humidity to the right. It’s a comparison I might possibly get to make on a rare 100 degree day in the rose city but certainly not on a 73 degree day in October.  Until now.

Okay To Skip This Part—read at your own risk! Tracking the relative humidity helps us do a quick comparison–but looking at Dew Points tells an even bigger story. The Dew Point, as you probably know, is how much you have to cool the air to make the invisible moisture appear. Usually, this is dew on the lawn or other surfaces. Hence the name. Fellow KOIN Local 6 Meteorologist Matt Brode and I looked up the Dew Point in all three cities. And Portland’s was about 10 degrees lower. If you run the ‘weather geek math’ on that one, it actually proved Portland’s air had about 30% less moisture in it on this October Friday afternoon than the air in Phoenix and Vegas. In other words, our air was absolutely much drier!

Facebook Weather Page Survey

Thanks to the more than 200 of you who went to my Facebook Weather Page and answered a simple question: Do you miss the rain? Yes or no. You see the results. A whopping 37% of us say yes, we miss the rain. 63% say no, this weather has been awesome. Thanks for the great comments some of you posted as well. It’s just fun knowing where we all stand on the issue!

Rain Ahead For Portland?
Some of our forecast tools are trying to bring in rain this coming Friday or Saturday, October 12th or 13th. We’ll see. These tools have made promises about the rainy season starting (that have never made it into my forecast because I doubted them) so don’t hold your breath on this one. Our record dry stretch is still rolling, for now.