Cordova, Alaska: Location and Climate

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Cordova is a remote Alaskan fishing town, with a year round population 2,400, accessible only by ferry or plane. We are in the bullseye center of 4 very different systems– to the north we are backed by an impenetrable fortress of mountains (with peaks ranging from 3,000-10,000 feet) and a nearly contiguous glacial cover; to the east is the Copper River Delta, fanning out in a braided expanse of silty sloughs and marshes 35 miles wide– the largest intact wetlands in the United States; to the south lies the big bad Gulf of Alaska, wide open to the Pacific ocean; and to the east, the protected marine waters and old-growth rainforest of Prince William Sound, the northern end of the Cascadia bioregion.

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Because of this juxtaposition, we get some very intense weather. It doesn’t get near as cold and dark as the interior and northern Alaska, but neither does it ever get very warm; and sun is typically displaced by clouds and heavy rain as the surrounding mountains catch the many Pacific storms whirling by.

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Cordova gets an average of 160 inches of precipitation per year. That’s more than thirteen feet of water. We also get some epic storms as you can see above, with winds frequently reaching “hurricane force” (74 mph). This doesn’t leave much time or space for what anyone, anywhere would consider good gardening weather.

Although we typically have at least 130 frost-free days and often considerably more because of our coastal influence, average peak summer temperatures are between 50 and 65 degrees– and even that ‘warm weather’ rarely lasts for more than two months. Many years see weeks on end of 40-50 degrees during those supposed “peak summer months.” On top of that, the late ‘summer’ harvest months are a deluge. August receives an average of 13 inches of rain, September an average of 22 inches of rain (and temperatures of 49 degrees) and October sees 21 inches. For a little perspective, Seattle, the self-named ‘Rainy City’ gets 38 inches per year.

To create a visual representation of our typical weather systems, and make sense out of the pages of data, I assembled this chart from NOAA’s Western Regional Climate Center, weather records for Cordova’s North Station.

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You can see the key to the main graph at the top there, but in case you can’t read the small writing, the vertical lines are, respectively:
yellow = spring equinox
pink = typical end of continuous snow cover (my own estimation)
dark green = reliable last 28 degree frost
light green = reliable last 32 degree frost
orange = solstice
yellow = fall equinox
light green = possible first 32 degree frost
dark green = possible first 28 degree frost
pink = typical beginning of lasting snow cover

Here on the coast, we are in USDA zone 7b, with minimum winter temperatures of 0 to -5. But, I feel like this is an inaccurately high zone number because of our completely inconsistent snow cover and rapidly changing winter weather. We can have a big snow (several feet) followed by warm weather, melting all the snow into a sodden ground, followed by a temperature dive to 5 degrees and a world coated with ice. It is a very hard place for roots. And fruit trees– if they survive the frozen ground, iced and snow laden branches, and multiple false springs– are unlikely to get enough hours of sun and heat to ripen fruit.

We also get some impressive winds here, as I mentioned. It can blow very hard, gusting to 80 miles/hour or more. The storms can last for days and occur with great frequency, particularly in the fall when one right after another can produce weeks of literally constant rain. Storms typically hit from the southeast, and cold winter winds blow down from the interior north. But because of the geography of the town and our site, we tend to experience both winds from the east as they blow through the gap in the mountains (that body of water on the right is a lake, to the left a protected inlet.)

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Here is another view of the town, seen from across the inlet, looking east.

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As you can see, the tight quarters and surrounding mountains block much of the solar possibilities, particularly in winter when the angle of the sun is exceptionally low. Here is a ‘polar coordinates’ chart from the University of Oregon’s solar calculator describing the path of the sun throughout the year. NOTE: I have flipped the chart (which is created with south at the top) to correspond with the above satellite image of the town. I realize that in permacultural design we are supposed to put the ‘sunward side’ at the top, but I haven’t quite gotten my head and maps around this yet.

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Here is another view (Cartesian coordinates) of the same information:

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As you can see, here at our high latitude (61 degrees N) the sun takes a very shallow path through the sky. Even at summer solstice when we have a potential 18 hours of sunlight, the solar “azimuth” or highest point is only 54 degrees (90 degrees being straight up, or zenith). At winter solstice we get a mere 6 hours of potential sunlight, and the sun doesn’t travel higher than 12 degrees!

When reviewing the solar data for this area, it must be kept in mind how few clear days we get. I wasn’t able to find any data on the percentage of clear days for our town, but averaging between the data for two nearby towns (Valdez and Yakutat) I estimate our annual average to be 45 days clear, 55 days partly cloudy and 265 days cloudy. Clear weather is most frequent in late winter, followed by spring and early summer (my own observation). Fall and early winter are typically very cloudy, as well as rainy and windy.

In short, I am trying to garden where the world’s wettest, coldest and darkest climates intersect. It’s brilliant.

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2 Responses to Cordova, Alaska: Location and Climate

  1. It was so interesting to read that, I did the same exercise for our place and it seems like it is the complete opposite climate. We worry about too much sun, not enough rain, high temperatures, and being close to the equator we have very little change in daylight hours between summer and winter. Both climates present challenges for the permaculturist, so I am looking forward to reading about your solutions!

  2. Nomads says:

    You both give me hope – if you can do this in such challenging locations, maybe I can actually achieve something somewhere a little easier!

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