Alaska Weather / Climate

Alaska’s geographical features play a significant role in its varying climatic conditions.  Due to the presence of different geographical areas, Alaska has various types of climate. The climate of Alaska depends mainly on the average temperatures and precipitations received by the state over many years. Alaska’s climate may vary from long frigid dark winters and brief cool summers in the Arctic region to the southern coastal region where the temperature falls below freezing point in winter.

Alaska Topography

Alaska has a total surface area of about 656,425 square miles out of which 570,374 square miles include the total land area and 86,051 square miles include the water area. Its land area includes variation in terrain from flat low lands to high mountain peaks. The coastal line is 33,000 miles long. Alaska has 12 major rivers and hundreds of lakes. Alaska has a number of mountain ranges. Two longest mountain ranges are the Alaska-Aleutian Range and the Brooks Range; other important ranges are The Chugash Mountain, Kenai Mountain and the Wrangell Mountain. The highest peak of Alaska is Mount McKinley which is about 20,320 feet above the sea level. Mount McKinley is located in South Central Alaska. In Alaska there are two distinct lowland areas formed from the drainage from mountains. They are Matanuska Valley and Susitna Valley. Permafrost is another major geographical feature of Alaska and it is a layer of soil at variable depth found under earth’s surface where the temperature has been below the freezing point for several thousand years. Alaska’s topography, thus, has a great impact on its temperature.

Climatic Zones of Alaska

Based on the monthly and annual average temperature and precipitation, the climate of Alaska falls into four major climatic zones. They are:

  1. Maritime Zone: The temperature in maritime zone usually reaches a maximum of 50 °F to 55°F or 10°C to 12°C during summer and drops to 23°F or -5°C during winter. Winds in maritime zone are typically between 13.8 mph (22.2km/h) to 20.7 mph (33.3km/h). The average precipitation in the maritime zone is about 40 inches per year. The maritime climatic zone includes south-eastern Alaska, the south coast and the south-western islands. In South-west Alaska the climate is greatly influenced by the near by Bering Sea. Its climate is long moderately cold during winter and cool, foggy, cloudy and breezy during winter.
  2. Continental Zone: The average temperature in the continental zone during summer season is around 60 °F or 15°C in the warmest month and the lowest temperature in this zone during winter season is -10°F (-23.3°C). Some times it may reach to an extremely cold temperature of -45°F (-42.7 °C) to -55°F (-48.3°C). The average precipitation in continental zone is about 10 inches (127-254 millimeters). This precipitation rate may exceed up to 20 inches in case when the terrain lifting acts as a factor in precipitation augmentation. During summer season the sun does not set for about one month. The interior Alaska has a continental zone climate with seasonal extremes. Alaska’s coldest and hottest places are located here. It mostly has a scanty precipitation with calm sunny whether. Long summer days make fishing more favorable in the interior Alaska from June to September.
  3. Transition Zone: The transition zone has two separate zones. The first transition zone is between the coastal zone and the Alaska Range. The summer temperature of this zone is higher than that of the maritime zone and the winter season is colder with less precipitation. It mainly includes Anchorage and the Matanuska valley. The next transition zone is in the west coast and it extends from Bristol Bay to Point Hope. The temperature in this zone is different from that of other. The summer usually is cooler than maritime temperature. Due to the presence of Ice Sea in the Bering and Chukchi, the winter season is usually cold.
  4. Arctic Zone: The arctic zone is generally located towards north of the Arctic Circle and the north of the Brooks Range including the Barrow and Prudhoe Bay. The summer in Arctic zone is very short and also very cool with a transition period in May and September. The winter is usually very cold and clear unlike summer which is cloudy. The average temperature in summer is around 50 °F (10°C) and in winter is around 11°F (-24°C). Average speed of wind is 30 miles per hour (48.3 km/h) and blows continuously through out year. The precipitation is very less and often lesser than 5 inches (254 millimeters) per year. The land area is marshy and has many lakes. This is due to the presence of permafrost. The permafrost is present under the entire Arctic region at a depth of 2,000 feet and thus adversely effects construction in this region.     

Changes In Alaska’s Climate

From last 30 years, the temperature in Alaska is getting changed in a faster manner than any other location of the world. An increase of 3.5°F in the annual average temperature was found in Alaska from 1949 – 2005. The winter season in Alaska is getting warmed by 6°F which is very much higher than the Global average of 1°F.

Far North Alaska - Barrow, Kotzebue, Nome, Prudhoe Bay

Temperature Shown in Fahrenheit High Low Daylight
May 24 14 23 hours
June 38 30 24 hours
July 45 33 24 hours
August 42 33 19 hours
September 34 27 13 hours

Interior Alaska - Fairbanks, Denali National Park

Temperature Shown in Fahrenheit High Low Daylight
May 59 38 18 hours
June 70 50 21 hours
July 72 52 20 hours
August 66 47 16 hours
September 54 36 13 hours

Southcentral Alaska - Anchorage, Seward, Talkeetna, Kenai

Temperature Shown in Fahrenheit High Low Daylight
May 54 39 17 hours
June 61 47 19 hours
July 65 51 18 hours
August 63 49 15 hours
September 55 41 13 hours

Southeast Alaska - Juneau, Ketchikan, Skagway

Temperature Shown in Fahrenheit High Low Daylight
May 55 38 16 hours
June 60 45 18 hours
July 64 48 17 hours
August 62 47 15 hours
September 55 43 13 hours

Alaska Average Temperature

  May June July August September
Anchorage 54°F 62°F 65°F 63°F 55°F
Fairbanks 70°F 70°F 75°F 70°F 64°F
Denali Park 58°F 68°F 70°F 64°F 53°F
Juneau 62°F 64°F 64°F 62°F 56°F
Ketchikan 56°F 61°F 65°F 65°F 60°F
Skagway 57°F 63°F 63°F 61°F 57°F
Vancouver 64°F 69°F 74°F 73°F 65°F

Alaska Average Precipitation

  May June July August September
Anchorage 0.73 in 1.14 in 1.71 in 2.44 in 2.70 in
Fairbanks 0.61 in 1.37 in 1.87 in 1.96 in 0.95 in
Denali Park 0.80 in 2.31 in 3.23 in 2.89 in 1.59 in
Juneau 3.42 in 3.15 in 4.16 in 5.32 in 6.73 in
Ketchikan 9.20 in 7.30 in 7.30 in 10.60 in 13.80 in
Skagway 1.53 in 1.12 in 1.12 in 2.19 in 4.06 in
Vancouver 2.43 in 1.80 in 1.42 in 1.50 in 2.54 in

Alaska Travel Guide