Tstoehr,

As the site says: "The widely recognized USDA climatic zones on the map below, although not absolute, give a good indication of plant hardiness." As mentioned, I inserted my Gaston Zip-code; it gave me a zone 6, with a minimum of -10 to 0 degrees. For the past 23 winters I've spent here, I've not seen it get below 5 degrees - close to 0, but 'warmer' than indicated by this map... Then I typed in my old Portland Zip and got zone 8, with its 10 - 20 degree minimum. Now 'back' in Portland I was too young to care how cold it got; but I'm sure this relatively 'warm' minimum doesn't include the East (or Coho) wind-chill factor out of the Columbia River Gorge!

Though a bit colder than family comparisons coming from Portland, I feel that near Gaston we'd be a perfect USDA Zone Seven - 0 to 10 degree minims. And personally, I'd rate Portland the same... Wadda ya do..? I found this map easier to use (just type in your zip-code) than the other hunt & guess maps with their microscopic delineation's. If you want to really brake it down, here on the West Coast, I'd suggest using the Sunset "Western Garden Book" - with their 24 pages on 24 Climate Zones! But strangely enough, from Roseburg to Longview, including both Gaston & Canby, they give everything a "Zone 6" rating!

That being, here's what the Sunset Western Garden Book says:

"Do not consider the lines on the maps to be rigid. Only in a very few places in the West are the climate-controlling factors so consistent that we can draw a line on the ground with a stick and say, "On this side of the line is climate X and on the other side, climate Y." In most cases, such a line would be nonsense. As the influence of each of the factors listed previously rises or falls, the lines shift gradually back and forth."

---That was a mouthfull - and I assume the USDA would give a similar 'disclaimer.' But I'll give the Garden Book one thing, their description of their Zone 6, the Willamette Valley, is one of the best I've read. In fact (I'm having to hand-type all this - no copy & paste option...), as the bulk of our Home Orchard Society live within this area - let me include it below:

"Zone 6, Willamette Valley" [from Sunset's Western Garden Book] "A somewhat longer growing season and warmer summers set the Willamette Valley climate off from the coast - Puget Sound climate (Zone 5). The Coast Range tempers the coastal winds and somewhat reduces the rainfall, but the climate of the valley is still essentially maritime much of the year, hence getting much less winter cold and less summer heat than areas east of the Cascades.
Average lows are similar to those of Zone 5 --even slightly colder in some places --but summer high temperatures average 5 to 9 degrees F. warmer, warm enough to put sugar in the 'Elberta' peaches and to speed growth of such evergreens as abelia and nandina. The long, mild growing season has made the Willamette Valley one of the West's great growing areas for nursery stock. Many of the West's (and the nation's) fruit and shade trees, deciduous shrubs, and broad-leafed evergreens start life here." [...finishing with roses & rhododendrons...]

Now, if we could all get on the same page... That was my hope, and if we all used the 'same map' - however accurate - it might provide a bit of info when, as suggested earlier, we 'tell where we're from.' "I'm from Zone 7?" - or was that zone 6..? " title="Embarassed" />

tstoehr,

I may have found 'their' answer! Scurrying around online I found the following site. They give more climatic info than we may ever care to ponder... But what hit me was how such zonal charts must be put together - research all historical lows (for instance), then chart to those numbers only?

For instance, within four days in January of 1950 (before my time), Hillsboro hit: -10, -9, & -9 degrees! The very next year (in the month of January) it dropped to 3 degrees... And I noticed (in Jan.) it got down to 8 degrees in Hillsboro in the years of 62 & 74.

Then I peeked at February of, 1989; this may be a couple we remember, it dropped to 9 one day, then 8 the next. On to Nov. of 1985, it hit 9 degrees, two days in a row. But back in 1972 (Go McGovern! ... which I do remember) it appears to have dropped to 3, 2, 5, 4, & 0... all in a row! And finally, in 1990, it got down to 6 degrees....

I only looked at Hillsboro because it's one I can relate to. For years Portland had taken their readings at PDX; excluding the wind-chill of the Columbia River Gorge, their records for decades were more moderate than the surrounding towns. My conclusion: The USDA crew go strictly by the worst, or lowest temperatures recorded - period. Thus, can't be blamed if we ever experience those extremes again - they told us so!

Here's the site, I'm sure its grist for Weatherman's banter around this state !

It's all located at: http://www.ocs.oregonstate.edu/index.html --- Once there; click on: Climate data - Zone 2 - Temperature & precipitation - under "Historical Averages:" hit the top-right "Daily means & records" - then hit your desired "Location."