Fort Knox Mine, Alaska climate: Climate normals at a NOAA weather station
Fort Knox Mine's normal year runs from −3°F January nights to 68°F July afternoons, with 18.5 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of −0.8°C, January lows of −19°C, July highs of 20°C, 470 mm of precipitation a year.
- NOAA stationFort Knox Mine
- Station IDUSC00503160
- Location65.00°N 147.34°W
- Elevation1,621 ft (494 m)
On October 23, the normal high in Fort Knox Mine is 27°F and the normal low 17°F, and the chance of measurable rain or snow is 29%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fort Knox Mine.
- Jan 10° -3°
- Feb 17° 1°
- Mar 23° 6°
- Apr 41° 23°
- May 57° 39°
- Jun 67° 49°
- Jul 68° 52°
- Aug 61° 46°
- Sep 50° 37°
- Oct 32° 21°
- Nov 17° 6°
- Dec 13° -1°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Fort Knox Mine each month?
July is the warmest month, with normal highs of 68°F; January the coldest, with normal lows of −3°F. The most precipitation falls in July (3.54 in), the least in April (0.45 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 10°F | −3°F | 3.5°F | 0.68 | 8 | <1 | 31 | 5 h |
| February | 17°F | 1°F | 9.3°F | 0.62 | 6 | <1 | 28 | 8 h 20 min |
| March | 23°F | 6°F | 14.6°F | 0.65 | 6 | <1 | 31 | 11 h 30 min |
| April | 41°F | 23°F | 31.9°F | 0.45 | 5 | <1 | 25 | 15 h 10 min |
| May | 57°F | 39°F | 47.7°F | 0.98 | 8 | <1 | 8 | 18 h 40 min |
| June | 67°F | 49°F | 58.0°F | 2.76 | 15 | <1 | <1 | 21 h 50 min |
| July | 68°F | 52°F | 60.1°F | 3.54 | 16 | <1 | <1 | 20 h 20 min |
| August | 61°F | 46°F | 53.6°F | 3.53 | 17 | <1 | <1 | 16 h 40 min |
| September | 50°F | 37°F | 43.5°F | 2.38 | 14 | <1 | 9 | 13 h 10 min |
| October | 32°F | 21°F | 26.8°F | 1.08 | 9 | <1 | 27 | 9 h 50 min |
| November | 17°F | 6°F | 11.3°F | 1.07 | 10 | <1 | 30 | 6 h 20 min |
| December | 13°F | −1°F | 6.3°F | 0.77 | 8 | <1 | 31 | 3 h 40 min |
| Year (annual) | 38°F | 23°F | 30.5°F | 18.51 | 120 | <1 | 221 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −12°C | −19°C | −15.8°C | 17 mm |
| February | −8°C | −17°C | −12.6°C | 16 mm |
| March | −5°C | −14°C | −9.7°C | 17 mm |
| April | 5°C | −5°C | −0.1°C | 11 mm |
| May | 14°C | 4°C | 8.7°C | 25 mm |
| June | 19°C | 10°C | 14.4°C | 70 mm |
| July | 20°C | 11°C | 15.6°C | 90 mm |
| August | 16°C | 8°C | 12.0°C | 90 mm |
| September | 10°C | 3°C | 6.4°C | 60 mm |
| October | 0°C | −6°C | −2.9°C | 27 mm |
| November | −8°C | −15°C | −11.5°C | 27 mm |
| December | −10°C | −18°C | −14.3°C | 20 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Gilmore Creek (6 miles away), gets 53 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00503160; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Fort Knox Mine?
Normal highs sit between 65°F and 85°F in June and July. Of those, June has the fewest days with rain (15).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00503160.
When is the last frost at Fort Knox Mine?
In Fort Knox Mine, the last spring frost (32°F) comes after May 12 in half of years and after May 28 in one year in ten; the first autumn frost comes before September 17 in half of years and before August 29 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 121 year in 10 after May 28; 9 in 10 after May 1
- First autumn frost, half of years before
- September 171 year in 10 before August 29; 9 in 10 before September 29
NOAA puts the median frost-free season at 126 days, and the season without a hard freeze (28°F) at 144 days.
A hard freeze (28°F) comes after May 4 in half of springs and before September 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fort Knox Mine in zone 2a in ZIP code 99705, the nearest ZIP area.
Frost dates for every NOAA station in Alaska · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00503160; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Fort Knox Mine?
In a normal year in Fort Knox Mine, a 90°F day is rare, 221 nights fall to 32°F or colder and 120 days bring measurable precipitation.
- Days at 90°F or more
- fewer than 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 221a normal year
- Days that stay below freezing
- 151high of 32°F or less
- Days with 0.01 inch of precipitation
- 120a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00503160.
How sunny is it at Fort Knox Mine?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds at Fort Knox Mine, 2.5 kWh per square metre a day. March is the sunniest month (86%) and October the cloudiest (61%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 76% | 0.1 |
| February | 77% | 0.8 |
| March | 86% | 2.6 |
| April | 85% | 4.5 |
| May | 73% | 5.2 |
| June | 69% | 5.5 |
| July | 65% | 4.7 |
| August | 65% | 3.5 |
| September | 66% | 2.2 |
| October | 61% | 0.9 |
| November | 66% | 0.2 |
| December | 82% | 0.0 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Fort Knox Mine record?
A normal year at Fort Knox Mine brings 12,571 heating degree days, 2.3 times the median U.S. place (5,373), and 37 cooling degree days, 96% fewer than the median (908). Ten months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 801 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,905 | 0 |
| February | 1,561 | 0 |
| March | 1,562 | 0 |
| April | 993 | 0 |
| May | 537 | 0 |
| June | 225 | 13 |
| July | 174 | 20 |
| August | 355 | 3 |
| September | 645 | 0 |
| October | 1,184 | 0 |
| November | 1,612 | 0 |
| December | 1,818 | 0 |
| Year (annual) | 12,571 | 37 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00503160. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Have recent years at Fort Knox Mine been warmer than normal?
2025 averaged 31.1°F, 0.6°F above the 1991-2020 normal of 30.5°F. 1 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 27.9°F | −2.6°F | 25.20 |
| 2022 | 30.0°F | −0.5°F | 14.87 |
| 2023 | 30.3°F | −0.2°F | 21.43 |
| 2025 | 31.1°F | +0.6°F | 19.35 |
Source: observed years: ACIS, station USC00503160. A year counts only with all twelve months complete.
How does Fort Knox Mine's climate compare?
Fort Knox Mine is warmer than 37 of the 85 places with their own NOAA record in Alaska, and wetter than 35. Across the 7,247 U.S. stations with normals, its annual mean of 30.5°F is warmer than 1%.
In the Köppen classification computed from these normals, Fort Knox Mine is Dfc: continental, no dry season, cool summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Questions about Fort Knox Mine's climate
What is the coldest month at Fort Knox Mine?
January, with a normal high of 10°F and a normal low of −3°F. The warmest is July (68°F by day, 52°F at night).
Does it snow at Fort Knox Mine?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Gilmore Creek (6 miles away), records 53 inches of snow in a normal year.
What is the rainiest month at Fort Knox Mine?
July, with 3.54 in of precipitation in a normal year; the driest is April with 0.45 in.
What plant hardiness zone is Fort Knox Mine in?
The USDA's 2023 map puts Fort Knox Mine in zone 2a in ZIP code 99705, the nearest ZIP area.
How late can frost come at Fort Knox Mine?
In half of years the last 32°F night comes after May 12; in one year in ten it comes after May 28. Waiting until May 28 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Alaska climateThe statewide normals and every place in the state
- Gilmore Creek, AK6 miles from this station, 28.4°F a year
- Fox, AK9 miles from this station, 27.8°F a year
- Two Rivers, AK15 miles from this station, 29.9°F a year
- Aurora, AK15 miles from this station, 28.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made