Climate of Anchorage

Climate chart for Anchorage

Anchorage, Alaska (Dena'ina: Dgheyay Kaq'; Dgheyaytnu)[1] has a subarctic climate with the code Dsc according to the Köppen climate classification due to its short, cool summers.[2] 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.[3] Anchorage is often cloudy during the winter, which decreases the amount of sunlight experienced by residents.

Temperature

Averages

Autumn in Eagle River AK

Average daytime summer temperatures range from approximately 55 to 78 °F (12.8 to 25.6 °C);[4] average daytime winter temperatures are about 5 to 30 °F (−15.0 to −1.1 °C).[4] Anchorage has a frost-free growing season that averages slightly over one hundred days. Average January low and high temperatures at Ted Stevens Anchorage International Airport (PANC) are 11 / 23 °F (−11.7 / −5.0 °C) with an average winter snowfall of 75.59 inches, or 1.92 meters. Farther afield at the Campbell Airstrip is another weather station recording colder night temperatures in both summer and winter.[4]

Average July low and high temperatures are 52 / 66 °F (11.1 / 18.9 °C) and the hottest reading ever recorded was 90 °F or 32.2 °C on July 4, 2019.[5]

Daily record warm minima

Precipitation

Rainfall

Between 2000 and 2022 the annual rainfall in Anchorage was 16.7 inches.[6] The months with the highest average mean of rain were August and September, each having an annual mean of 2.75 inches (August) and 3.24 inches (September).

Snowfall

Winter view of Anchorage and the Chugach Mountains

For snowfall, the annual mean average for 2000 to 2022 was 76.4 inches;[7] the highest snowfall season being 2011 - 2012 with 134.5 inches, and the lowest season being 25.1 inches in 2015.

Climate change

Based on the ERA5 data published by ECMWF, the annual mean temperature of Anchorage has increased from 0.8 °C in 1940 to 3.8 °C in 2022, an increase of 3 °C. [8] The mayor and the assembly of Anchorage in 2019 issued a climate action plan for the anticipated effects that climate change will have on its city and people.[9] The action plan includes all of the municipality of Anchorage, as far north as Eklutna and as south as Portage. One of the major goals of the climate action plan is to reduce green house gas emissions by 80% by the year 2050 from its 2008 emission levels. The first annual report on this came out in 2021. For its near term plans, the city also introduced a plan called the "Municipality of Anchorage Climate Action Strategy."

Anchorage
Climate chart (explanation)
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0.7
 
 
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0.6
 
 
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40
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1.2
 
 
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1.1
 
 
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█ Average max. and min. temperatures in °F
█ Precipitation totals in inches
Metric conversion
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−5
−12
 
 
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−3
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█ Average max. and min. temperatures in °C
█ Precipitation totals in mm

Notable climate events

Due to its proximity to active volcanoes, ash hazards are a significant, though infrequent, occurrence. The most recent notable incident was an August 1992 mark of Mt. Spurr, which is located 78 mi (126 km) west of the city.[needs update] The eruption deposited about 3 mm (0.12 in) of volcanic ash on the city.[10] The cleanup of ash resulted in excessive demands for water and caused major problems for the Anchorage Water and Wastewater Utility.[citation needed]

On March 17, 2002, there was a storm that caused 28.6 in of snow to close schools for two days.[11] The storm broke the city record for the most snowfall in a single day. The storm beat the previous record from 1955 on March 16, which was just 15.6 inches. The National Weather Service also recorded this same snow data.[12]

Classifications

Anchorage Climate according to major climate systems
Climatic scheme Initials Description
Köppen system[13] Dfc Continental subarctic climate[a]
Trewartha system[14][15] E Boreal climate
Alisov system[16] — Temperate climate[b]
Strahler system[17] — Boreal forest climate
Thornthwaite system[18]
B1 C'1
 Humid and microthermal
Neef system[19][20] — West side/maritime climate

NWS office/international airport

Climate data for Ted Stevens Anchorage International Airport, Alaska (1991−2020 normals,[21] extremes 1953−present)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °F (°C) 50
(10) 		49
(9) 		53
(12) 		69
(21) 		77
(25) 		85
(29) 		90
(32) 		82
(28) 		73
(23) 		64
(18) 		54
(12) 		51
(11) 		90
(32)
Mean maximum °F (°C) 41.8
(5.4) 		42.7
(5.9) 		44.2
(6.8) 		56.3
(13.5) 		69.5
(20.8) 		74.5
(23.6) 		76.0
(24.4) 		73.7
(23.2) 		65.0
(18.3) 		54.8
(12.7) 		42.7
(5.9) 		42.3
(5.7) 		77.7
(25.4)
Mean daily maximum °F (°C) 22.7
(−5.2) 		27.3
(−2.6) 		33.0
(0.6) 		45.1
(7.3) 		56.3
(13.5) 		63.4
(17.4) 		66.2
(19.0) 		64.0
(17.8) 		55.7
(13.2) 		42.0
(5.6) 		28.9
(−1.7) 		25.0
(−3.9) 		44.1
(6.7)
Daily mean °F (°C) 16.9
(−8.4) 		21.3
(−5.9) 		25.8
(−3.4) 		37.5
(3.1) 		48.1
(8.9) 		55.9
(13.3) 		59.6
(15.3) 		57.5
(14.2) 		49.3
(9.6) 		36.3
(2.4) 		23.6
(−4.7) 		19.4
(−7.0) 		37.6
(3.1)
Mean daily minimum °F (°C) 11.0
(−11.7) 		15.2
(−9.3) 		18.6
(−7.4) 		29.9
(−1.2) 		40.0
(4.4) 		48.4
(9.1) 		52.9
(11.6) 		50.9
(10.5) 		42.9
(6.1) 		30.7
(−0.7) 		18.3
(−7.6) 		13.8
(−10.1) 		31.0
(−0.6)
Mean minimum °F (°C) −9.3
(−22.9) 		−3.6
(−19.8) 		1.2
(−17.1) 		17.6
(−8.0) 		30.7
(−0.7) 		40.5
(4.7) 		46.7
(8.2) 		42.7
(5.9) 		30.9
(−0.6) 		16.1
(−8.8) 		0.8
(−17.3) 		−4.9
(−20.5) 		−13.2
(−25.1)
Record low °F (°C) −34
(−37) 		−28
(−33) 		−24
(−31) 		−4
(−20) 		17
(−8) 		33
(1) 		36
(2) 		31
(−1) 		19
(−7) 		−5
(−21) 		−21
(−29) 		−30
(−34) 		−34
(−37)
Average precipitation inches (mm) 0.75
(19) 		0.86
(22) 		0.69
(18) 		0.43
(11) 		0.65
(17) 		1.02
(26) 		1.82
(46) 		2.93
(74) 		3.10
(79) 		1.82
(46) 		1.19
(30) 		1.16
(29) 		16.42
(417)
Average snowfall inches (cm) 12.4
(31) 		13.4
(34) 		11.0
(28) 		4.0
(10) 		0.3
(0.76) 		0.0
(0.0) 		0.0
(0.0) 		0.0
(0.0) 		0.4
(1.0) 		5.6
(14) 		12.6
(32) 		18.2
(46) 		77.9
(198)
Average extreme snow depth inches (cm) 16.4
(42) 		19.0
(48) 		19.9
(51) 		12.7
(32) 		0.3
(0.76) 		0.0
(0.0) 		0.0
(0.0) 		0.0
(0.0) 		0.2
(0.51) 		3.2
(8.1) 		8.8
(22) 		14.7
(37) 		24.5
(62)
Average precipitation days (≥ 0.01 in) 8.1 7.9 6.0 4.9 6.5 8.6 11.7 14.4 14.9 11.5 9.8 10.8 115.1
Average snowy days (≥ 0.1 in) 8.8 7.8 6.1 2.5 0.3 0.0 0.0 0.0 0.3 3.2 7.7 10.8 47.5
Average relative humidity (%) 73.4 71.4 66.1 64.3 61.6 65.6 71.4 75.1 75.9 74.5 77.1 77.1 71.1
Average dew point °F (°C) 8.1
(−13.3) 		11.1
(−11.6) 		15.4
(−9.2) 		24.1
(−4.4) 		33.4
(0.8) 		42.4
(5.8) 		48.6
(9.2) 		47.8
(8.8) 		40.6
(4.8) 		27.0
(−2.8) 		15.3
(−9.3) 		10.6
(−11.9) 		27.0
(−2.8)
Mean monthly sunshine hours 82.9 120.5 195.8 235.3 288.7 274.7 250.1 203.9 159.8 117.1 80.6 51.8 2,061.2
Percent possible sunshine 41 48 53 53 53 48 44 42 41 38 37 30 46
Average ultraviolet index 0 0 1 2 4 5 5 4 2 1 0 0 2
Source 1: NOAA (relative humidity and sun 1961–1990)[22][23][24]
Source 2: Weather Atlas (UV)[25]
Climate data for Anchorage
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Average sea temperature °F (°C) 36.9
(2.8) 		35.8
(2.1) 		36.1
(2.3) 		37.5
(3.0) 		42.4
(5.8) 		47.7
(8.8) 		52.4
(11.3) 		53.1
(11.7) 		51.6
(10.9) 		47.5
(8.6) 		43.0
(6.1) 		39.6
(4.2) 		43.6
(6.5)
Mean daily daylight hours 7.0 9.0 12.0 15.0 18.0 19.0 18.0 16.0 13.0 10.0 7.0 6.0 12.5
Source: Weather Atlas[25]

See or edit raw graph data.

Campbell airstrip

Climate data for Campbell airstrip (Anchorage Alaska)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Mean daily maximum °F (°C) 20
(−7) 		26
(−3) 		35
(2) 		45
(7) 		58
(14) 		66
(19) 		68
(20) 		65
(18) 		55
(13) 		41
(5) 		26
(−3) 		22
(−6) 		44
(7)
Mean daily minimum °F (°C) 2
(−17) 		4
(−16) 		9
(−13) 		22
(−6) 		33
(1) 		41
(5) 		47
(8) 		44
(7) 		35
(2) 		22
(−6) 		7
(−14) 		5
(−15) 		23
(−5)
Average snowfall inches (cm) 10
(25) 		16
(41) 		18
(46) 		9
(23) 		0.2
(0.51) 		0
(0) 		0
(0) 		0
(0) 		0
(0) 		9
(23) 		11
(28) 		2
(5.1) 		75.2
(191.61)
Source: NOAA[4]

Merrill Field

Climate data for Merrill Field (1991−2020 normals,[c] extremes 1914−present)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °F (°C) 56
(13) 		57
(14) 		56
(13) 		71
(22) 		92
(33) 		100
(38) 		93
(34) 		90
(32) 		73
(23) 		67
(19) 		62
(17) 		54
(12) 		100
(38)
Mean maximum °F (°C) 42.5
(5.8) 		44.0
(6.7) 		45.2
(7.3) 		58.4
(14.7) 		71.2
(21.8) 		76.7
(24.8) 		79.0
(26.1) 		76.5
(24.7) 		66.2
(19.0) 		56.3
(13.5) 		43.5
(6.4) 		44.5
(6.9) 		80.5
(26.9)
Mean daily maximum °F (°C) 22.6
(−5.2) 		28.0
(−2.2) 		34.4
(1.3) 		47.1
(8.4) 		58.4
(14.7) 		65.7
(18.7) 		68.4
(20.2) 		65.7
(18.7) 		56.8
(13.8) 		42.5
(5.8) 		29.0
(−1.7) 		24.7
(−4.1) 		45.3
(7.4)
Daily mean °F (°C) 15.4
(−9.2) 		20.2
(−6.6) 		25.6
(−3.6) 		38.8
(3.8) 		49.7
(9.8) 		57.7
(14.3) 		61.1
(16.2) 		58.5
(14.7) 		49.8
(9.9) 		36.4
(2.4) 		22.6
(−5.2) 		18.0
(−7.8) 		37.8
(3.2)
Mean daily minimum °F (°C) 8.2
(−13.2) 		12.4
(−10.9) 		16.9
(−8.4) 		30.4
(−0.9) 		41.1
(5.1) 		49.7
(9.8) 		53.9
(12.2) 		51.3
(10.7) 		42.8
(6.0) 		30.3
(−0.9) 		16.3
(−8.7) 		11.3
(−11.5) 		30.4
(−0.9)
Mean minimum °F (°C) −10.8
(−23.8) 		−5.6
(−20.9) 		−1.5
(−18.6) 		16.7
(−8.5) 		32.0
(0.0) 		41.9
(5.5) 		47.2
(8.4) 		42.2
(5.7) 		30.3
(−0.9) 		15.7
(−9.1) 		−1.1
(−18.4) 		−7.3
(−21.8) 		−15.0
(−26.1)
Record low °F (°C) −35
(−37) 		−38
(−39) 		−20
(−29) 		−21
(−29) 		1
(−17) 		29
(−2) 		34
(1) 		31
(−1) 		19
(−7) 		−6
(−21) 		−22
(−30) 		−36
(−38) 		−38
(−39)
Average precipitation inches (mm) 0.46
(12) 		0.71
(18) 		0.54
(14) 		0.30
(7.6) 		0.62
(16) 		0.99
(25) 		1.70
(43) 		2.48
(63) 		3.02
(77) 		1.57
(40) 		0.88
(22) 		0.89
(23) 		14.16
(360)
Average precipitation days (≥ 0.01 in) 6.0 6.4 6.0 4.5 6.5 9.9 12.4 15.6 15.0 11.4 7.4 8.1 109.2
Source: NOAA[26][27]

Notes

  1. ^ Or only subarctic climate
  2. ^ Mid-latitude temperate interior climate
  3. ^ Mean monthly maxima and minima (i.e. the highest and lowest temperature readings during an entire month or year) calculated based on data at said location from 1991 to 2020.

References

  1. ^ Alsworth, Mailing Address: PO Box 227 Port; Us, AK 99653 Phone: 907 644-3626 Contact. "Dena'ina Athabascan Culture - Lake Clark National Park & Preserve (U.S. National Park Service)". www.nps.gov. Retrieved 2022-04-06.{{cite web}}: CS1 maint: numeric names: authors list (link)
  2. ^ Society, National Geographic (2019-10-24). "Köppen Climate Classification System". National Geographic Society. Retrieved 2022-04-07.
  3. ^ "Shortest Day In Alaska | Hours of Daylight & Winter Darkness Fun Facts". ALASKA.ORG. Retrieved 2022-04-07.
  4. ^ a b c d "NOWData - NOAA Online Weather Data". NOAA. 2023-06-26.
  5. ^ a b "xmACIS2". National Oceanic and Atmospheric Administration. Retrieved June 26, 2023.
  6. ^ US Department of Commerce, NOAA. "Climate". www.weather.gov. Retrieved 2022-04-05.
  7. ^ US Department of Commerce, NOAA. "Climate". www.weather.gov. Retrieved 2022-04-06.
  8. ^ "ERA5 Climate Change Data". Oikolab. Retrieved 2023-07-23.
  9. ^ "Municipality of Anchorage". Municipality of Anchorage. Retrieved 2022-04-06.
  10. ^ "Mt. Spurr's 1992 Eruptions". 2008-12-09. Archived from the original on 9 December 2008. Retrieved 2022-04-06.
  11. ^ "Anchorage Receives Record Snowfall". www.earthobservatory.nasa.gov. 2002-03-19. Retrieved 2022-04-07.
  12. ^ "National Weather Service, Anchorage Forecast Office Climate". 2011-07-28. Archived from the original on 28 July 2011. Retrieved 2022-04-06.
  13. ^ "Anchorage - University of Alaska, Alaska Köppen Climate Classification (Weatherbase)". Weatherbase. Retrieved 2019-07-03.
  14. ^ "GLOBAL ECOLOGICAL ZONING FOR THE GLOBAL FOREST RESOURCES ASSESSMENT 2000". www.fao.org. Retrieved 2019-07-01.
  15. ^ "Trewartha maps". kkh.ltrr.arizona.edu. Retrieved 2019-07-03.
  16. ^ Cmapm, Kliimavöötmed svg: Urmasderivative work (2011-06-16), Русский: Климатические пояса Земли по Б. П. Алисову., retrieved 2019-07-01
  17. ^ "World Strahler Climate Map".
  18. ^ Feddema, Johannes J. (January 2005). "A Revised Thornthwaite-Type Global Climate Classification". Physical Geography. 26 (6): 442–466. Bibcode:2005PhGeo..26..442F. doi:10.2747/0272-3646.26.6.442. ISSN 0272-3646. S2CID 128745497.
  19. ^ "Klimaklassifikation". www.spektrum.de (in German). Retrieved 2019-07-01.
  20. ^ "Klimazonen nach E. Neef (1989)". Klett-Perthes.
  21. ^ Mean monthly maxima and minima (i.e. the highest and lowest temperature readings during an entire month or year) calculated based on data at said location from 1991 to 2020.
  22. ^ "NowData – NOAA Online Weather Data". National Oceanic and Atmospheric Administration. Retrieved May 29, 2021.
  23. ^ "Station: Anchorage INTL AP, AK". U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991–2020). National Oceanic and Atmospheric Administration. Archived from the original on 2023-07-14. Retrieved May 29, 2021.
  24. ^ "WMO climate normals for Anchorage/INTL, AK 1961−1990". National Oceanic and Atmospheric Administration. Archived from the original on 2023-07-14. Retrieved August 30, 2020.
  25. ^ a b "Anchorage, Alaska, USA - Monthly weather forecast and Climate data". Weather Atlas. Retrieved July 4, 2019.
  26. ^ "Station: ANCHORAGE MERRILL FLD, AK". U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991–2020). National Oceanic and Atmospheric Administration. Archived from the original on 2023-08-30. Retrieved August 30, 2023.
  27. ^ "xmACIS2". National Oceanic and Atmospheric Administration. Retrieved August 30, 2023.