Oregon climates

Jane McGary janemcgary@earthlink.net
Wed, 19 Jul 2006 18:45:04 PDT
Dell asked,
At 02:31 PM 7/19/2006 -0400, you wrote:

>Dear Jane and Joyce and others who live in Oregon,
>I recently visited relatives in Tigard, OR (SW of Portland) and traveled to
>the vicinity of Mt Hood, the fruit growing region on the northeast of the
>mountain. I know that in CA, the climate/zone/temps and rainfall can vary
>dramatically from east to west. My relatives told me that in Tigard, there
>is very little snow and temps rarely get lower than 25F. Is this also true
>of Gresham, Estacada, and other towns east of Portland?

No, it is not. Towns east of Portland, especially Gresham, Sandy, and 
Troutdale, are subject to continental east winds through the Columbia 
Gorge, which can drop the temperature drastically in winter and raise it in 
summer. The Estacada area, where I live, experiences somewhat less severe 
east winds through the Clackamas River gap in the Cascades.  Tigard is 
nearly at sea level (I think about 40 feet elevation) in the flat 
Willamette Valley, whereas my land is at 1600 feet in the Cascade 
foothills  (southwwest of Mt. Hood) and is usually 5 to 10 degrees F colder 
than the Portland airport, which is in turn somewhat colder than it would 
be in Tigard, West Linn, Lake Oswego, and some of the other suburbs 
southwest of the Portland city center. However, these western suburbs can 
experience colder temperatures when an inversion layer associated with the 
Coast Range lies above them. Snowfall in the Portland area occurs quite 
variably and is much more common above 1000 feet elevation -- such as on 
the high ridges west of the city center, or in areas to the east such as 
where I live. Such microclimatic variation is typical of parts of the 
western USA near high mountains and major rivers.

Jane McGary
Northwestern Oregon, USA

More information about the pbs mailing list