Keystone Ridge, Alaska climate: Climate normals at a NOAA weather station
Keystone Ridge's normal year runs from −1°F January nights to 69°F July afternoons, with 17.2 inches of precipitation and 78 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of −0.4°C, January lows of −19°C, July highs of 21°C, 438 mm of precipitation a year.
- NOAA stationKeystone Ridge
- Station IDUSC00504621
- Location64.92°N 148.27°W
- Elevation1,600 ft (488 m)
On October 23, the normal high in Keystone Ridge is 27°F and the normal low 18°F, and the chance of measurable rain or snow is 36%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Keystone Ridge.
- Jan 10° -1°
- Feb 17° 4°
- Mar 23° 8°
- Apr 42° 25°
- May 58° 38°
- Jun 68° 49°
- Jul 69° 51°
- Aug 61° 47°
- Sep 50° 37°
- Oct 32° 22°
- Nov 18° 7°
- Dec 14° 2°
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 Keystone Ridge each month?
July is the warmest month, with normal highs of 69°F; January the coldest, with normal lows of −1°F. The most precipitation falls in August (3.17 in), the least in April (0.58 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 10°F | −1°F | 4.3°F | 0.74 | 9.5 | 9 | <1 | 31 | 5 h |
| February | 17°F | 4°F | 10.5°F | 0.72 | 11.6 | 8 | <1 | 28 | 8 h 20 min |
| March | 23°F | 8°F | 15.5°F | 0.63 | 7.8 | 7 | <1 | 31 | 11 h 30 min |
| April | 42°F | 25°F | 33.0°F | 0.58 | 6.5 | 5 | <1 | 23 | 15 h |
| May | 58°F | 38°F | 48.1°F | 0.98 | 2.0 | 9 | <1 | 7 | 18 h 30 min |
| June | 68°F | 49°F | 58.5°F | 2.56 | 0.0 | 13 | <1 | <1 | 21 h 40 min |
| July | 69°F | 51°F | 60.0°F | 3.01 | 0.0 | 16 | <1 | <1 | 20 h 20 min |
| August | 61°F | 47°F | 54.0°F | 3.17 | 0.0 | 17 | <1 | <1 | 16 h 40 min |
| September | 50°F | 37°F | 43.3°F | 2.05 | 2.7 | 14 | <1 | 7 | 13 h 10 min |
| October | 32°F | 22°F | 26.8°F | 0.99 | 11.1 | 11 | <1 | 26 | 9 h 50 min |
| November | 18°F | 7°F | 12.3°F | 1.10 | 15.4 | 10 | <1 | 30 | 6 h 20 min |
| December | 14°F | 2°F | 7.6°F | 0.70 | 11.2 | 9 | <1 | 31 | 3 h 50 min |
| Year (annual) | 38°F | 24°F | 31.2°F | 17.23 | 77.8 | 128 | <1 | 214 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −12°C | −19°C | −15.4°C | 19 mm | 24 cm |
| February | −8°C | −15°C | −11.9°C | 18 mm | 29 cm |
| March | −5°C | −13°C | −9.2°C | 16 mm | 20 cm |
| April | 5°C | −4°C | 0.6°C | 15 mm | 17 cm |
| May | 14°C | 4°C | 8.9°C | 25 mm | 5 cm |
| June | 20°C | 9°C | 14.7°C | 65 mm | 0 cm |
| July | 21°C | 11°C | 15.6°C | 76 mm | 0 cm |
| August | 16°C | 8°C | 12.2°C | 81 mm | 0 cm |
| September | 10°C | 3°C | 6.3°C | 52 mm | 7 cm |
| October | 0°C | −6°C | −2.9°C | 25 mm | 28 cm |
| November | −8°C | −14°C | −10.9°C | 28 mm | 39 cm |
| December | −10°C | −17°C | −13.6°C | 18 mm | 28 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00504621; 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 Keystone Ridge?
Normal highs sit between 65°F and 85°F in June and July. Of those, June has the fewest days with rain (13).
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 USC00504621.
When is the last frost at Keystone Ridge?
In Keystone Ridge, the last spring frost (32°F) comes after May 15 in half of years and after May 31 in one year in ten; the first autumn frost comes before September 16 in half of years and before August 30 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 151 year in 10 after May 31; 9 in 10 after May 3
- First autumn frost, half of years before
- September 161 year in 10 before August 30; 9 in 10 before September 28
NOAA puts the median frost-free season at 122 days, and the season without a hard freeze (28°F) at 140 days.
A hard freeze (28°F) comes after May 7 in half of springs and before September 25 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Keystone Ridge in zone 3b in ZIP code 99709, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 3b: the coldest night of a typical year reaches −31°F (23 complete years).
Frost dates for every NOAA station in Alaska · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00504621; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. 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 Keystone Ridge?
In a normal year in Keystone Ridge, a 90°F day is rare, 214 nights fall to 32°F or colder and 128 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
- 214a normal year
- Days that stay below freezing
- 156high of 32°F or less
- Days with 0.01 inch of precipitation
- 128a normal year
- Days with 1 inch of snow or more
- 25a normal year
The highest temperature in this station's record (since 1996) is 88°F, on June 25, 2013; the lowest is −44°F, on February 3, 1999.
The wettest calendar year on that record is 2024, with 22.65 in; the snowiest season is 2017–18, with 127.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00504621; records: ACIS (NOAA Regional Climate Centers), station USC00504621. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Keystone Ridge?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds at Keystone Ridge, 2.6 kWh per square metre a day. March is the sunniest month (85%) and October the cloudiest (61%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 0.2 |
| February | 76% | 0.9 |
| March | 85% | 2.6 |
| April | 84% | 4.5 |
| May | 75% | 5.3 |
| June | 71% | 5.6 |
| July | 67% | 4.8 |
| August | 68% | 3.7 |
| September | 68% | 2.4 |
| October | 61% | 0.9 |
| November | 63% | 0.3 |
| December | 78% | 0.1 |
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 Keystone Ridge record?
A normal year at Keystone Ridge brings 12,363 heating degree days, 2.3 times the median U.S. place (5,373), and 50 cooling degree days, 94% 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 829 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,882 | 0 |
| February | 1,525 | 0 |
| March | 1,534 | 0 |
| April | 959 | 0 |
| May | 525 | 1 |
| June | 216 | 20 |
| July | 180 | 23 |
| August | 348 | 6 |
| September | 650 | 0 |
| October | 1,184 | 0 |
| November | 1,582 | 0 |
| December | 1,779 | 0 |
| Year (annual) | 12,363 | 50 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00504621. 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 Keystone Ridge been warmer than normal?
2025 averaged 32.7°F, 1.5°F above the 1991-2020 normal of 31.2°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 29.4°F | −1.8°F | – | – |
| 2022 | 31.5°F | +0.3°F | 12.00 | 78.8 |
| 2023 | 31.4°F | +0.2°F | 17.57 | 121.8 |
| 2024 | 31.6°F | +0.4°F | 22.65 | 79.1 |
| 2025 | 32.7°F | +1.5°F | 19.22 | 76.1 |
Source: observed years: ACIS, station USC00504621. A year counts only with all twelve months complete.
How does Keystone Ridge's climate compare?
Keystone Ridge is warmer than 37 of the 85 places with their own NOAA record in Alaska, and wetter than 31. Across the 7,247 U.S. stations with normals, its annual mean of 31.2°F is warmer than 1%.
In the Köppen classification computed from these normals, Keystone Ridge 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.
Which places near Keystone Ridge share this climate record?
Livengood has no NOAA station with 1991-2020 normals of its own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Livengood, AK11 people · 39 mi N
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Keystone Ridge's climate
What is the coldest month at Keystone Ridge?
January, with a normal high of 10°F and a normal low of −1°F. The warmest is July (69°F by day, 51°F at night).
Does it snow at Keystone Ridge?
Yes: 78 inches in a normal year, falling on 69 days with 0.1 inch or more, the most in November (15.4 inches).
What is the rainiest month at Keystone Ridge?
August, with 3.17 in of precipitation in a normal year; the driest is April with 0.58 in.
What plant hardiness zone is Keystone Ridge in?
The USDA's 2023 map puts Keystone Ridge in zone 3b in ZIP code 99709, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −31°F (23 years, 1991-2020): zone 3b.
How late can frost come at Keystone Ridge?
In half of years the last 32°F night comes after May 15; in one year in ten it comes after May 31. Waiting until May 31 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Alaska climateThe statewide normals and every place in the state
- Ester, AK9 miles from this station, 26.8°F a year
- Goldstream, AK12 miles from this station, 24.3°F a year
- University Experiment Station, AK12 miles from this station, 28.9°F a year
- College, AK13 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