The climate of Alaska is determined by average temperatures and precipitation received statewide over many years. The extratropical storm track runs along the Aleutian Island chain, across the Alaska Peninsula, and along the coastal area of the Gulf of Alaska which exposes these parts of the state to a large majority of the storms crossing the North Pacific. The climate in Juneau and the southeast panhandle is a mid-latitude oceanic climate (similar to Scotland, or Haida Gwaii), (Köppen Cfb) in the southern sections and a subarctic oceanic climate (Köppen Cfc) in the northern parts. The climate in Southcentral Alaska is a subarctic climate (Köppen Dfc) due to its short, cool summers. The climate of the interior of Alaska is best described as extreme and is the best example of a true subarctic climate, as the highest and lowest recorded temperatures in Alaska have both occurred in the interior. The climate in the extreme north of Alaska is an Arctic climate (Köppen ET) with long, cold winters, and cool summers where snow is possible year-round.
The climate in Juneau and the Southeast panhandle is a mid-latitude oceanic climate (Köppen climate classification Cfb) in the southern sections and an oceanic, marine subpolar climate (similar to Scotland, or Haida Gwaii), (Köppen Cfc) in the northern parts. Much of the southern parts are temperate rainforest. On an annual basis, southern portions are both the wettest and warmest part of Alaska, with milder temperatures in the winter and high precipitation throughout the year. Average monthly precipitation is generally highest in the autumn months, especially October, and lowest in May or June. This is also the only region in Alaska in which the average daytime high temperature is above freezing during the winter months, except for in the southern parts of the Aleutian Islands such as Unalaska.
The climate in south central Alaska, with Anchorage as a typical city, is mild by Alaskan standards. This is due in large part to its proximity to the coast. While it does not get nearly as much rain as the southeast of Alaska, it does get more snow, although days tend to be clearer there. It is a subarctic climate (Köppen Dfc) due to its short, cool summers. There are frequent, strong southeast winds known as the Knik wind in the vicinity of Palmer, especially in the winter months. [1]
The climate of Western Alaska is determined largely by the Bering Sea and the Gulf of Alaska. It is a subarctic oceanic climate in the southwest and a continental subarctic climate farther north. The temperature is somewhat moderate considering how far north the area is. This area has a tremendous amount of variety, especially when considering precipitation. The northern side of the Seward Peninsula is technically a desert with less than 10 inches (254 mm) of precipitation annually, while some locations between Dillingham and Bethel average around 100 inches (2,540 mm) of precipitation. [2]
The climate of the east of Alaska is best described as extreme and is an excellent example of a true continental subarctic climate. Some of the hottest and coldest temperatures in Alaska occur around the area near Fairbanks. The summers can have temperatures reaching into the 90s °F (near 34 °C), while in the winter, the temperature can fall below −50 °F (−45.6 °C), and in rare cases, below −60 °F (−51.1 °C). Precipitation is generally sparse around the year, peaking during the summer months, and virtually all precipitation between October and April falls as snow. Ice fog is a significant hazard during especially cold periods between November and March. [3]
The climate in the extreme north of Alaska is what would be expected for an area north of the Arctic Circle. It is an Arctic climate (Köppen E) with long, very cold winters and short, cool summers. The sun does not rise at all during some weeks in the winter, and is out for 24 hours during some weeks in the summer. However, despite 24 hours of sunshine in the summertime, the average low temperature is barely above freezing in Utqiaġvik in July, at 36 °F (2.2 °C) and snow may fall any month of the year. [4] North Alaska is the coldest region in Alaska. [3]
City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Anchorage | 23 / 11 (−5 / −12) | 28 / 16 (−2 / −9) | 34 / 18 (1 / −8) | 46 / 30 (8 / −1) | 57 / 40 (14 / 4) | 64 / 48 (18 / 9) | 66 / 53 (19 / 12) | 64 / 51 (18 / 11) | 56 / 43 (13 / 6) | 42 / 31 (6 / −1) | 29 / 18 (−2 / −8) | 25 / 14 (−4 / −10) |
Utqiaġvik | −4 / −18 (−20 / −28) | −4 / −18 (−20 / −28) | −3 / −17 (−19 / −27) | 12 / −2 (−11 / −19) | 28 / 18 (−2 / −8) | 43 / 31 (6 / −1) | 49 / 36 (9 / 2) | 46 / 35 (8 / 2) | 38 / 30 (3 / −1) | 27 / 17 (−3 / −8) | 13 / 0 (−11 / −18) | 1 / −12 (−17 / −24) |
Fairbanks | 1 / −17 (−17 / −27) | 12 / −11 (−11 / −24) | 25 / −3 (−4 / −19) | 46 / 22 (8 / −6) | 62 / 39 (17 / 4) | 72 / 50 (22 / 10) | 73 / 53 (23 / 12) | 66 / 48 (19 / 9) | 55 / 36 (13 / 2) | 34 / 18 (1 / −8) | 12 / −4 (−11 / −20) | 4 / −13 (−16 / −25) |
Fort Yukon | −8 / −22 | 2 / −18 (−17 / −28) | 16 / −8 (−9 / −22) | 39 / 17 (4 / −8) | 60 / 38 (16 / 3) | 72 / 51 (22 / 11) | 74 / 53 (23 / 12) | 66 / 46 (19 / 8) | 52 / 34 (11 / 1) | 30 / 17 (−1 / −8) | 3 / −10 (−16 / −23) | −4 / −18 (−20 / −28) |
Juneau (downtown) | 34 / 27 (1 / −3) | 37 / 28 (3 / −2) | 40 / 30 (4 / −1) | 49 / 36 (9 / 2) | 57 / 43 (14 / 6) | 62 / 49 (17 / 9) | 64 / 52 (18 / 11) | 63 / 51 (17 / 11) | 57 / 46 (14 / 8) | 49 / 39 (9 / 4) | 40 / 32 (4 / 0) | 36 / 29 (2 / −2) |
Sitka | 41 / 32 (5 / 0) | 41 / 32 (5 / 0) | 42 / 33 (6 / 1) | 48 / 37 (9 / 3) | 54 / 43 (12 / 6) | 58 / 48 (14 / 9) | 60 / 53 (16 / 12) | 62 / 53 (17 / 12) | 58 / 49 (14 / 9) | 51 / 42 (11 / 6) | 44 / 36 (7 / 2) | 42 / 33 (6 / 1) |
Craig | 39 / 33 (4 / 1) | 40 / 32 (4 / 0) | 42 / 33 (6 / 1) | 47 / 37 (8 / 3) | 53 / 43 (12 / 6) | 57 / 48 (14 / 9) | 59 / 52 (15 / 11) | 61 / 53 (16 / 12) | 57 / 48 (14 / 9) | 50 / 42 (10 / 6) | 43 / 36 (6 / 2) | 40 / 34 (4 / 1) |
Kodiak | 36 / 26 (2 / −3) | 38 / 27 (3 / −3) | 39 / 28 (4 / −2) | 45 / 34 (7 / 1) | 52 / 40 (11 / 4) | 57 / 46 (14 / 8) | 62 / 50 (17 / 10) | 63 / 50 (17 / 10) | 57 / 44 (14 / 7) | 48 / 36 (9 / 2) | 40 / 30 (4 / −1) | 37 / 27 (3 / −3) |
Kotzebue | 6 / −7 | 10 / −5 (−12 / −21) | 10 / −5 (−12 / −21) | 25 / 10 (−4 / −12) | 40 / 29 (4 / −2) | 55 / 43 (13 / 6) | 61 / 52 (16 / 11) | 58 / 49 (14 / 9) | 49 / 40 (9 / 4) | 32 / 24 (0 / −4) | 17 / 7 (−8 / −14) | 10 / −3 (−12 / −19) |
Nome | 13 / −2 (−11 / −19) | 17 / 1 (−8 / −17) | 18 / 2 (−8 / −17) | 29 / 16 (−2 / −9) | 44 / 31 (7 / −1) | 55 / 42 (13 / 6) | 58 / 46 (14 / 8) | 56 / 44 (13 / 7) | 49 / 37 (9 / 3) | 36 / 25 (2 / −4) | 24 / 12 (−4 / −11) | 16 / 2 (−9 / −17) |
Unalaska | 37 / 29 (3 / −2) | 38 / 30 (3 / −1) | 39 / 30 (4 / −1) | 41 / 33 (5 / 1) | 46 / 38 (8 / 3) | 52 / 43 (11 / 6) | 57 / 47 (14 / 8) | 59 / 49 (15 / 9) | 54 / 45 (12 / 7) | 48 / 39 (9 / 4) | 43 / 34 (6 / 1) | 39 / 31 (4 / −1) |
St. Paul | 29 / 21 (−2 / −6) | 29 / 21 (−2 / −6) | 29 / 20 (−2 / −7) | 34 / 26 (1 / −3) | 40 / 32 (4 / 0) | 47 / 38 (8 / 3) | 51 / 44 (11 / 7) | 53 / 46 (12 / 8) | 50 / 41 (10 / 5) | 43 / 35 (6 / 2) | 37 / 30 (3 / −1) | 33 / 24 (1 / −4) |
The highest and lowest recorded temperatures in Alaska are both in the Interior. The highest is 100 °F (37.8 °C) in Fort Yukon on June 27, 1915. [5] [6] [7] [8] The lowest Alaska temperature is −80 °F (−62.2 °C) in Prospect Creek on January 23, 1971, [5] [6] 1 °F (0.6 °C) above the lowest temperature recorded in continental North America (in Snag, Yukon, Canada). [9] Alaska also holds the extreme US record low temperatures for every month except September and October.
Climate data for Alaska (averages based on the years of 1991-2020) | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Record high °F (°C) | 67 (19) | 66 (19) | 71 (22) | 82 (28) | 93 (34) | 100 (38) | 99 (37) | 99 (37) | 90 (32) | 76 (24) | 67 (19) | 67 (19) | 100 (38) |
Mean daily maximum °F (°C) | 10.7 (−11.8) | 16.2 (−8.8) | 21.2 (−6.0) | 35 (2) | 49 (9) | 59.9 (15.5) | 62.3 (16.8) | 58 (14) | 48.3 (9.1) | 33.3 (0.7) | 19.2 (−7.1) | 13.3 (−10.4) | 35.5 (1.9) |
Daily mean °F (°C) | 4.2 (−15.4) | 8.7 (−12.9) | 12.3 (−10.9) | 26.2 (−3.2) | 40.1 (4.5) | 50.9 (10.5) | 54.1 (12.3) | 50.4 (10.2) | 41.4 (5.2) | 27.3 (−2.6) | 13.3 (−10.4) | 7 (−14) | 28.0 (−2.2) |
Mean daily minimum °F (°C) | −2.4 (−19.1) | 1.2 (−17.1) | 3.5 (−15.8) | 17.4 (−8.1) | 31.2 (−0.4) | 41.9 (5.5) | 45.9 (7.7) | 42.8 (6.0) | 34.5 (1.4) | 21.2 (−6.0) | 7.3 (−13.7) | 0.7 (−17.4) | 20.4 (−6.4) |
Record low °F (°C) | −80 (−62) | −75 (−59) | −68 (−56) | −50 (−46) | −25 (−32) | −11 (−24) | 8 (−13) | −6 (−21) | −13 (−25) | −48 (−44) | −62 (−52) | −72 (−58) | −80 (−62) |
Average precipitation inches (mm) | 2.82 (72) | 2.39 (61) | 2.11 (54) | 1.90 (48) | 2.12 (54) | 2.42 (61) | 3.48 (88) | 4.57 (116) | 4.96 (126) | 4.23 (107) | 3.50 (89) | 3.14 (80) | 37.64 (956) |
Source 1: NOAA Climate at A Glance [10] | |||||||||||||
Source 2: http://wrcc.dri.edu/summary/Climsmak.html |
Juneau averages over 50 inches (1,270 mm) of precipitation a year, while some other areas in southeast Alaska receive as much as 275 inches (6,980 mm). Average monthly precipitation generally peaks in September or October, and is lowest in May and June. Owing to the rain shadow of the coastal mountains, south-central Alaska does not get nearly as much rain as the southeast of Alaska, though it does get more snow with up to 300 inches (7.62 m) at Valdez and much more in the mountains. On average, Anchorage receives 16 inches (410 mm) of precipitation a year, with around 75 inches (1.91 m) of snow. The northern coast of the Gulf of Alaska receives up to 150 inches (3,810.0 mm) of precipitation annually. [11] Across the western sections of the state, the northern side of the Seward Peninsula is a desert with less than 10 inches (250 mm) of precipitation annually, while some locations between Dillingham and Bethel average around 100 inches (2,540 mm) of precipitation. [12]
Inland, often less than 10 inches (254 mm) falls a year and on the North Slope as little as 4 inches (100 mm) of rainfall equivalent and 30 inches (0.76 m) of snow is typical, but what snow falls during the winter tends to stay throughout the season. [2] Thunderstorms are fairly rare in most of Alaska, but do occur in the interior in the summer with some frequency and may cause wildfires. Anchorage gets a thunderstorm every few years. There has even been the rare thunderstorm in Utqiaġvik on the Arctic coast. [13] While weak tornadoes and waterspouts, while extremely rare, do sometimes occur, Alaska is considered the least tornado-prone state in the United States.
La Niña events lead to drier and cooler than normal conditions, while El Niño events leads to warmer than normal temperatures but do not have a correlation towards dry or wet conditions. Precipitation increases by 10–40% when the Pacific decadal oscillation is positive. [14]
Interior Alaska is the central region of Alaska's territory, roughly bounded by the Alaska Range to the south and the Brooks Range to the north. It is largely wilderness. Mountains include Denali in the Alaska Range, the Wrangell Mountains, and the Ray Mountains. The native people of the interior are Alaskan Athabaskans. The largest city in the interior is Fairbanks, Alaska's second-largest city, in the Tanana Valley. Other towns include North Pole, just southeast of Fairbanks, Eagle, Tok, Glennallen, Delta Junction, Nenana, Anderson, Healy and Cantwell. The interior region has an estimated population of 113,154.
The polar climate regions are characterized by a lack of warm summers but with varying winters. Every month a polar climate has an average temperature of less than 10 °C (50 °F). Regions with a polar climate cover more than 20% of the Earth's area. Most of these regions are far from the equator and near the poles, and in this case, winter days are extremely short and summer days are extremely long. A polar climate consists of cool summers and very cold winters, which results in treeless tundra, glaciers, or a permanent or semi-permanent layer of ice. It is identified with the letter E in the Köppen climate classification.
The subarctic climate is a continental climate with long, cold winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of an ocean, generally at latitudes from 50°N to 70°N, poleward of the humid continental climates. Subarctic or boreal climates are the source regions for the cold air that affects temperate latitudes to the south in winter. These climates represent Köppen climate classification Dfc, Dwc, Dsc, Dfd, Dwd and Dsd.
Missouri generally has a variety of seasonal humid subtropical climate, with cool winters and long, hot summers. In the southern part of the state, particularly in the Bootheel, the climate borders on a more mild-type humid subtropical climate, and in the northern third, the state transitions into a humid continental climate. Because of its location in the interior United States, Missouri often experiences extremes in temperatures. Lacking either large mountains or oceans nearby to moderate its temperature, its climate is alternately influenced by air from the cold Arctic and the hot and humid Gulf of Mexico.
In climatology, the term microthermal is used to denote the continental climates of Eurasia and North America.
The climate of Salt Lake City, Utah features cold and snowy winters, hot and dry summers, and modest to light seasonal rainfall. Lying in the Salt Lake Valley, the city is surrounded by mountains and the Great Salt Lake. Under the Köppen climate classification, Salt Lake City has either a Mediterranean climate (Csa) or dry-summer continental climate (Dsa) depending on which variant of the system is used, though it borders on a cold semi-arid climate (BSk) due to the city's relatively low precipitation.
The climate of Minneapolis–Saint Paul is the long term weather trends and historical events of the Minneapolis–Saint Paul metropolitan area in east central Minnesota. Minneapolis and St. Paul, together known as the Twin Cities, are the core of the 15th largest metropolitan area in the United States. With a population of 3.6 million people, the region contains approximately 60% of the population of Minnesota. Due to its location in the northern and central portion of the U.S., the Twin Cities has the coldest average temperature of any major metropolitan area in the nation. Winters are very cold, summer is warm and humid, snowfall is common in the winter and thunderstorms with heavy rainfall occur during the spring, summer and autumn. Though winter can be cold, the area receives more sunlight hours in mid-winter than many other warmer parts of the country, including all of the Great Lakes states, the Pacific Northwest, parts of the South, and almost all of the Northeast. Unless otherwise indicated, all normals data presented below are based on data at Minneapolis/St. Paul International Airport, the official Twin Cities climatology station, from the 1981−2010 normals period.
Milwaukee has a humid continental climate, with four distinct seasons and wide variations in temperature and precipitation in short periods of time. The city's climate is also strongly influenced by nearby Lake Michigan, which creates two varying climates within the Milwaukee area. The Urban heat island effect also plays a role in the city's climate, insulating it from winter cold, but keeping it cooler in spring and summer.
Minnesota has a humid continental climate, with hot summers and cold winters. Minnesota's location in the Upper Midwest allows it to experience some of the widest variety of weather in the United States, with each of the four seasons having its own distinct characteristics. The area near Lake Superior in the Minnesota Arrowhead region experiences weather unique from the rest of the state. The moderating effect of Lake Superior keeps the surrounding area relatively cooler in the summer and warmer in the winter, giving that region a smaller yearly temperature variation. On the Köppen climate classification, much of the southern third of Minnesota—roughly from the Twin Cities region southward—falls in the hot summer zone (Dfa), and the northern two-thirds of Minnesota falls in the warm summer zone (Dfb).
The climate of the north and central parts of the U.S. state of Florida is humid subtropical. South Florida has a tropical climate. There is a defined rainy season from May through October when air mass thundershowers that build in the heat of the day drop heavy but brief summer rainfall.
Alaska occupies the northwestern portion of the North American continent and is bordered only by Canada on the east. It is one of two U.S. states not bordered by another state; Hawaii is the other. Alaska has more ocean coastline than all of the other U.S. states combined. About 500 miles (800 km) of Canadian territory separate Alaska from Washington state. Alaska is thus an exclave of the United States that is part of the continental U.S. and the U.S. West Coast, but is not part of the contiguous U.S.
North Dakota's climate is typical of a continental climate with cold winters and warm-hot summers. The state's location in the Upper Midwest allows it to experience some of the widest variety of weather in the United States, and each of the four seasons has its own distinct characteristics. The eastern half of the state has a humid continental climate with warm to hot, somewhat humid summers and cold, windy winters, while the western half has a semi-arid climate with less precipitation and less humidity but similar temperature profiles. The areas east of the Missouri River get slightly colder winters, while those west of the stream get higher summer daytime temperatures. In general, the diurnal temperature difference is prone to be more significant in the west due to higher elevation and less humidity.
The climate of the Arctic is characterized by long, cold winters and short, cool summers. There is a large amount of variability in climate across the Arctic, but all regions experience extremes of solar radiation in both summer and winter. Some parts of the Arctic are covered by ice year-round, and nearly all parts of the Arctic experience long periods with some form of ice on the surface.
The climate of the United States varies due to changes in latitude, and a range of geographic features, including mountains and deserts. Generally, on the mainland, the climate of the U.S. becomes warmer the further south one travels, and drier the further west, until one reaches the West Coast.
North Carolina's climate varies from the Atlantic coast in the east to the Appalachian Mountain range in the west. The mountains often act as a "shield", blocking low temperatures and storms from the Midwest from entering the Piedmont of North Carolina.
Anchorage, Alaska has a subarctic climate with the code Dfc according to the Köppen climate classification due to its short, cool summers. The weather on any given day is very unpredictable. Some winters feature several feet of snow and cold temperatures, while the summers are typically mild but are cool compared to the contiguous US and interior Alaska. Because of Anchorage's high latitude, summer days are very long and winter daylight hours are very short. The longest day of sunlight being 18hrs and 21 minutes, and shortest being 5 hours and 28 minutes. Anchorage is often cloudy during the winter, which decreases the amount of sunlight experienced by residents.
The climate of Norway is more temperate than could be expected for such high latitudes. This is mainly due to the North Atlantic Current with its extension, the Norwegian Current, raising the air temperature; the prevailing southwesterlies bringing mild air onshore; and the general southwest–northeast orientation of the coast, which allows the westerlies to penetrate into the Arctic. The January average in Brønnøysund is 15.8C (28.6F) higher than the January average in Nome, Alaska, even though both towns are situated on the west coast of the continents at 65°N. In July the difference is reduced to 3.2C (5.8F). The January average of Yakutsk, in Siberia but slightly further south, is 42.3C (76.1F) lower than in Brønnøysund.
The climate of Los Angeles is mild to hot year-round, and mostly dry. It is classified as a Mediterranean climate, which is a type of subtropical climate. It is characterized by seasonal changes in rainfall—with a dry summer and a winter rainy season. Under the Köppen climate classification, the coastal areas are classified as Csb, and the inland areas as Csa.
Prospect Creek is a very small settlement approximately 180 miles (290 km) north of present-day Fairbanks and 25 miles (40 km) southeast of present-day Bettles, Alaska. Years ago it was home to numerous mining expeditions and the camp for the building of the Trans-Alaska Pipeline System (TAPS). Today, it is the location of Pump Station 5 of the TAPS. Prospect Creek is also home to the United States record for lowest temperature. On January 23, 1971 the record low temperature of −79.8 °F (−62.1 °C) was recorded. Wildlife can be found there even with its extreme changes in temperature; local fauna include anything from black and brown bears to bald eagles. The elevation of Prospect Creek is 643 feet (196 m) above sea level. Nearby Moore Creek is widely known for its gold and quartz mining and sits alongside Prospect Creek in Alaska’s Innoko Mining District. The Innoko Mining District is famous for its findings of large quartz.
According to the Köppen climate classification, most of Western Oregon has a warm-summer Mediterranean climate, which features warm, dry summers, and wet winters with frequent overcast and cloudy skies. Eastern Oregon falls into the cold semi-arid climate, which features drier weather.