Climate & Weather
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The coastal weather patterns are formed when the warm, moist marine air driven by the pacific current across the Gulf of Alaska and hits the coastal mountain range. An average of one storm every four or five days crosses the gulf between October and April. When the storms attempt to reach equilibrium with inland air masses while being squeezed over glaciers and through narrow river/mountain passes, wind conditions can exceed hurricane force.
Because of these seasonally unpredictable wind and sea conditions, mariners have referred to the section of coastline between Icy Bay and Cape Clear as coffin corner. Seas exceeding 65 feet are known, and seas to 30 feet common during cyclonic storms in fall and winter, when winds are often 40 knots, and sometimes exceed 100 knots. Precipitation in the area can reach 300 inches per year, although the average along the river delta is probably closer to 150 inches, including up to 80 inches of snow. During calm weather there is often a "kiss of the Copper", strong offshore winds at the mouth of the river caused when high air pressure from the interior flows down the Copper River valley. September is the rainiest month, with an average of 40 inches, while June is the driest.
Related
5th Field HUC (hydrology) Map
Hydrology Interactive Map
Sunrise over the Copper River Delta
Native Village of Eyak research camp
Coastal temperatures are considered mild, with summer temperatures in the 60°s, and winter temperatures in the mid-30°s.
Just over the coastal mountain range it is a different story, with summer temperatures sometimes reaching into the 90°, and winter temperatures approaching 40° below zero. The upper areas of the Copper River Basin experience about one-fifth of coastal precipitation, and annual precipitation averages less than 12 inches in the interior region.
Interior/Continental Climate Zone: Interior Alaska experiences seasonal temperature extremes. January temperatures average from -22° to -2°; July temperatures average 50° to 72°. Annual precipitation is 11.3 inches.
Chistochina: Long, cold winters and warm summers. Temperature extremes: -62° to 91°. Snowfall averages 61 inches. Annual precipitation: 13 inches.
Chitina: Long, cold winters and warm summers. Temperature extremes: -58° to 91°. Snowfall averages 52 inches. Annual precipitation: 12 inches.
Kluti-Kah / Copper Center: Cold winters and warm summers. Temperature extremes: -74° to 96°. Snowfall averages 39 inches; Total precipitation: 9 inches per year.
Copperville: Long, cold winters and warm summers. Temperature extremes: -74° to 96°. Snowfall averages 39 inches and precipitation is 9 inches per year.
Gakona: Long, cold winters and relatively warm summers. Temperature extremes: -62° to 91°. Snowfall averages 61 inches, with total precipitation of 13 inches per year.
Glennallen: Long, cold winters and relatively warm summers. The mean temperature is -10° in January, and 56° in July. Snowfall averages 39 inches, with total precipitation of 9 inches per year.
Kenny Lake: Long, cold winters and relatively warm summers. Temperature extremes: -58° to 91°. Snowfall averages 52 inches, with total precipitation of 12 inches per year.
McCarthy: Long cold winters and relatively warm summers. Temperature extremes: -58° to 91°. Snowfall averages 52 inches, with total precipitation of 12 inches per year.
Mendeltna: Long cold winters and relatively warm summers Temperature extremes: -74° to 96°. Snowfall averages 39 inches, with total precipitation of 9 inches per year.
Nelchina: Long cold winters and relatively warm summers. Temperature extremes: -74° to 96°. Snowfall averages 39 inches, with total precipitation of 9 inches per year.
Paxson: Long cold winters and relatively warm summers. January temperatures average from -22° to -2°; July temperatures average 50° to 72°. Annual precipitation is 11.3 inches.
Slana: Long, cold winters and relatively warm summers. Temperature extremes: -62° to 91°. Snowfall averages 61 inches, with total precipitation of 13 inches per year.
Tazlina: Long cold winters and relatively warm summers. Temperature extremes: -74° to 96°. Snowfall averages 39 inches, with total annual precipitation of 9 inches.
Coastal Temperate Rainforest: The Copper River Delta area is the northernmost section of the Pacific Temperate rainforest.
Eyak / Cordova: Coastal Temperate Rainforest. Winter temperatures average from 17° to 32°; summer temperatures average 49° to 63°. Annual precipitation: 167 inches, including 80 inches of snowfall. Temperature extremes: -20° to 82°.
