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Weather & Climate in Koyukuk, AK
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Koyukuk has a cool climate with an average annual temperature of 26°F (-3°C). Winters average -10°F in January while summers reach 60°F in July / a wide seasonal temperature swing of 70°F. The area gets 274 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 13.9 inches (drier than the 38-inch national average). The area receives 77.2 inches of snow annually, making winter weather a significant factor for residents. Air quality is rated Good with a median AQI of 21 / among the cleanest air in the country. The city sits at an elevation of 322 feet.
Temperature
-10°F Jan (-23°C)
60°F Jul (16°C)
| Annual Average | 26.0°F |
| 52% below US avg | |
| January Average | -10°F (-23°C) |
| July Average | 60°F (16°C) |
| Sunny Days | 274 days/yr |
Geography
| Elevation | 322 ft (98 m) |
| Area | 5.8 sq mi (14.9 km²) |
| Population Density | 8/sq mi |
| Coordinates | 64.9021°N, 157.6935°W |
| Timezone | America/Anchorage |
| County | Northwest Arctic Borough County |
| Nearest Airport | Fairbanks International (FAI) 289 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 21.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 54.6 / 100 |
| Social Vulnerability | 99.8 / 100 |
| Community Resilience | 5.9 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Earthquake | Relatively Low |
| Wildfire | Relatively Low |
| Flood | Very Low |
| Hail | No Rating |
| Strong Wind | No Rating |
| Winter Weather | Relatively Moderate |
| Lightning | Very Low |
| Ice Storm | Very Low |
| Drought | No Rating |
| Cold Wave | Relatively High |
| Landslide | Relatively Low |
| Coastal Flood | No Rating |
| Volcano | Very Low |
| Avalanche | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
118 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.9.
| Nov 5, 1997 | 19 km ENE of Ruby, Alaska | M4.9 | 122 km | 10 km |
| May 17, 1999 | 15 km ENE of Kaltag, Alaska | M4.5 | 68 km | 10 km |
| Jul 6, 2006 | 36 km NNE of Koyuk, Alaska | M4.5 | 149 km | 10 km |
| Jan 10, 2001 | 54 km SW of Hughes, Alaska | M4.4 | 149 km | 10 km |
| Sep 13, 1998 | 26 km S of Nulato, Alaska | M4.2 | 50 km | 10 km |
| May 3, 2019 | 68 km NNW of Huslia, Alaska | M4.0 | 149 km | 6 km |
| Nov 21, 2000 | 26 km ENE of Kaltag, Alaska | M3.9 | 57 km | 10 km |
| Feb 6, 2001 | 31 km W of Kaltag, Alaska | M3.8 | 102 km | 22 km |
| Mar 4, 1996 | 21 km ENE of Huslia, Alaska | M3.7 | 124 km | 15 km |
| Feb 9, 2019 | 92 km SSW of Shungnak, Alaska | M3.6 | 144 km | 12 km |
| May 26, 2023 | 31 km ENE of Huslia, Alaska | M3.6 | 137 km | 10 km |
| Jan 22, 1992 | 51 km NE of Unalakleet, Alaska | M3.5 | 139 km | -3 km |
| Dec 26, 1999 | 56 km SW of Hughes, Alaska | M3.5 | 148 km | 10 km |
| Oct 4, 2000 | 16 km ENE of Kaltag, Alaska | M3.5 | 66 km | 9 km |
| Oct 22, 2003 | 99 km NNW of Koyukuk, Alaska | M3.5 | 97 km | 33 km |
| Nov 30, 1994 | 23 km E of Ruby, Alaska | M3.5 | 128 km | 25 km |
| Jun 23, 2020 | 48 km ENE of Shaktoolik, Alaska | M3.4 | 130 km | 7 km |
| Aug 28, 2019 | 10 km NNE of Ruby, Alaska | M3.4 | 107 km | 16 km |
| Apr 29, 2021 | 20 km ENE of Kaltag, Alaska | M3.4 | 66 km | 14 km |
| Apr 7, 2022 | 49 km NNW of Koyukuk, Alaska | M3.3 | 47 km | 13 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: BONANZA CREEK (241,856 acres, 2004).
| Year | Name | Acres Burned | Distance |
| 2004 | BONANZA CREEK | 241,856 | 39 km |
| 2005 | HOLTNATKATNA CREEK | 204,488 | 60 km |
| 2015 | HOLTNAKATNA | 180,266 | 94 km |
| 2015 | THREE DAY | 89,983 | 94 km |
| 2015 | DULBI RIVER | 84,988 | 75 km |
| 2005 | EAST FORK YUKI RIVER | 79,220 | 100 km |
| 2000 | YUKON CREEK | 68,820 | 75 km |
| 1990 | GAL N 38 | 61,375 | 59 km |
| 2005 | GISASA RIVER | 51,057 | 48 km |
| 2022 | MUD RIVER | 49,997 | 97 km |
| 2007 | COFFEE CAN LAKE | 41,717 | 62 km |
| 2015 | YUKON CREEK | 39,035 | 69 km |
| 2015 | NULATO | 35,728 | 25 km |
| 2005 | LITTLE MUD RIVER 2 | 33,080 | 93 km |
| 1988 | 831024 | 25,914 | 100 km |
| 2004 | LOUIS LAKE | 24,323 | 41 km |
| 2002 | HOLTNAKA | 23,023 | 77 km |
| 2019 | LOUIS LAKE | 22,720 | 49 km |
| 2015 | BARE MT | 22,514 | 96 km |
| 2015 | ILLINOIS MINE | 21,968 | 94 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | -10°F (-23°C) | 0.7 in | Coldest |
| February | 2°F (-17°C) | 0.8 in | |
| March | 8°F (-13°C) | 0.6 in | |
| April | 25°F (-4°C) | 0.6 in | |
| May | 42°F (6°C) | 0.4 in | Driest |
| June | 56°F (13°C) | 1.1 in | |
| July | 60°F (16°C) | 2.1 in | Warmest |
| August | 54°F (12°C) | 2.5 in | Wettest |
| September | 44°F (7°C) | 1.4 in | |
| October | 26°F (-3°C) | 0.9 in | |
| November | 8°F (-13°C) | 0.9 in | |
| December | -1°F (-19°C) | 0.8 in |
Koyukuk has a seasonal temperature swing of 70°F / from -10°F in January to 60°F in July. Total annual precipitation is 12.7 inches, with August being the wettest month (2.5") and May the driest (0.4").