Port Alcan, Alaska climate: Climate normals at a NOAA weather station
Port Alcan's normal year runs from −19°F January nights to 69°F July afternoons, with 11.0 inches of precipitation and 27 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of −4.4°C, January lows of −28°C, July highs of 21°C, 279 mm of precipitation a year.
- NOAA stationPort Alcan
- Station IDUSC00507513
- Location62.62°N 141.01°W
- Elevation1,892 ft (577 m)
On October 23, the normal high in Port Alcan is 25°F and the normal low 9°F, and the chance of measurable rain or snow is 18%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Port Alcan.
- Jan -5° -19°
- Feb 6° -13°
- Mar 23° -6°
- Apr 43° 17°
- May 58° 33°
- Jun 67° 44°
- Jul 69° 47°
- Aug 65° 41°
- Sep 53° 30°
- Oct 31° 14°
- Nov 8° -7°
- Dec -2° -16°
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 Port Alcan each month?
July is the warmest month, with normal highs of 69°F; January the coldest, with normal lows of −19°F. The most precipitation falls in July (2.71 in), the least in March (0.14 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | −5°F | −19°F | -12.1°F | 0.26 | 3.5 | 4 | <1 | 31 | 5 h 50 min |
| February | 6°F | −13°F | -3.4°F | 0.26 | 2.9 | 3 | <1 | 28 | 8 h 50 min |
| March | 23°F | −6°F | 8.4°F | 0.14 | 3.0 | 2 | <1 | 31 | 11 h 40 min |
| April | 43°F | 17°F | 29.7°F | 0.21 | 0.9 | 2 | <1 | 29 | 14 h 50 min |
| May | 58°F | 33°F | 45.6°F | 0.88 | 0.7 | 6 | <1 | 13 | 17 h 50 min |
| June | 67°F | 44°F | 55.3°F | 2.23 | 0.0 | 13 | <1 | 1 | 20 h |
| July | 69°F | 47°F | 57.9°F | 2.71 | 0.0 | 13 | <1 | <1 | 19 h 10 min |
| August | 65°F | 41°F | 53.0°F | 1.73 | 0.0 | 11 | <1 | 2 | 16 h 10 min |
| September | 53°F | 30°F | 41.5°F | 1.02 | 0.5 | 8 | <1 | 19 | 13 h 10 min |
| October | 31°F | 14°F | 22.6°F | 0.51 | 4.1 | 5 | <1 | 31 | 10 h 10 min |
| November | 8°F | −7°F | 0.3°F | 0.65 | 7.1 | 6 | <1 | 30 | 7 h |
| December | −2°F | −16°F | -9.3°F | 0.39 | 4.7 | 5 | <1 | 31 | 5 h |
| Year (annual) | 35°F | 14°F | 24.1°F | 10.99 | 27.4 | 77 | <1 | 246 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −21°C | −28°C | −24.5°C | 7 mm | 9 cm |
| February | −14°C | −25°C | −19.7°C | 7 mm | 7 cm |
| March | −5°C | −21°C | −13.1°C | 4 mm | 8 cm |
| April | 6°C | −8°C | −1.3°C | 5 mm | 2 cm |
| May | 14°C | 1°C | 7.6°C | 22 mm | 2 cm |
| June | 19°C | 6°C | 12.9°C | 57 mm | 0 cm |
| July | 21°C | 8°C | 14.4°C | 69 mm | 0 cm |
| August | 18°C | 5°C | 11.7°C | 44 mm | 0 cm |
| September | 12°C | −1°C | 5.3°C | 26 mm | 1 cm |
| October | −1°C | −10°C | −5.2°C | 13 mm | 10 cm |
| November | −14°C | −22°C | −17.6°C | 17 mm | 18 cm |
| December | −19°C | −27°C | −22.9°C | 10 mm | 12 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00507513; 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 Port Alcan?
Normal highs sit between 65°F and 85°F in June, July and August. Of those, August has the fewest days with rain (11).
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 USC00507513.
When is the last frost at Port Alcan?
In Port Alcan, the last spring frost (32°F) comes after May 28 in half of years and after June 10 in one year in ten; the first autumn frost comes before August 29 in half of years and before August 14 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 281 year in 10 after June 10; 9 in 10 after May 15
- First autumn frost, half of years before
- August 291 year in 10 before August 14; 9 in 10 before September 8
NOAA puts the median frost-free season at 91 days, and the season without a hard freeze (28°F) at 115 days.
A hard freeze (28°F) comes after May 15 in half of springs and before September 9 in half of autumns.
By the USDA's method, the average of each year's coldest night over 1991-2020, the station is in plant hardiness zone 2a: the coldest night of a typical year reaches −47°F (15 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 USC00507513; 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 Port Alcan?
In a normal year in Port Alcan, a 90°F day is rare, 246 nights fall to 32°F or colder and 77 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
- 246a normal year
- Days that stay below freezing
- 163high of 32°F or less
- Days with 0.01 inch of precipitation
- 77a normal year
- Days with 1 inch of snow or more
- 11a normal year
The highest temperature in this station's record (since 1985) is 94°F, on July 12, 2004; the lowest is −56°F, on February 3, 1993.
The wettest calendar year on that record is 2010, with 18.82 in; the snowiest season is 2021–22, with 61.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00507513; records: ACIS (NOAA Regional Climate Centers), station USC00507513. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Port Alcan?
Over a year 69% of the sunlight that would reach the ground under clear skies gets through the clouds at Port Alcan, 2.7 kWh per square metre a day. April is the sunniest month (78%) and November the cloudiest (59%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 0.3 |
| February | 70% | 1.0 |
| March | 78% | 2.6 |
| April | 78% | 4.4 |
| May | 70% | 5.1 |
| June | 67% | 5.4 |
| July | 65% | 4.9 |
| August | 68% | 4.0 |
| September | 67% | 2.5 |
| October | 60% | 1.1 |
| November | 59% | 0.3 |
| December | 63% | 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 Port Alcan record?
A normal year at Port Alcan brings 14,873 heating degree days, 2.8 times the median U.S. place (5,373), and 10 cooling degree days, 99% 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 593 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 2,392 | 0 |
| February | 1,915 | 0 |
| March | 1,753 | 0 |
| April | 1,058 | 0 |
| May | 603 | 0 |
| June | 297 | 6 |
| July | 223 | 4 |
| August | 373 | 1 |
| September | 704 | 0 |
| October | 1,313 | 0 |
| November | 1,942 | 0 |
| December | 2,302 | 0 |
| Year (annual) | 14,873 | 10 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00507513. 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 Port Alcan been warmer than normal?
2023 averaged 25.7°F, 1.6°F above the 1991-2020 normal of 24.1°F. 2 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 22.9°F | −1.2°F | 11.47 | 62.4 |
| 2022 | 25.1°F | +0.9°F | 14.56 | 69.0 |
| 2023 | 25.7°F | +1.6°F | – | – |
Source: observed years: ACIS, station USC00507513. A year counts only with all twelve months complete.
How does Port Alcan's climate compare?
Port Alcan is warmer than 10 of the 85 places with their own NOAA record in Alaska, and wetter than 5. Across the 7,247 U.S. stations with normals, its annual mean of 24.1°F is warmer than 0%.
In the Köppen classification computed from these normals, Port Alcan is Dsc: continental, dry-summer, 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 Port Alcan's climate
What is the coldest month at Port Alcan?
January, with a normal high of −5°F and a normal low of −19°F. The warmest is July (69°F by day, 47°F at night).
Does it snow at Port Alcan?
Yes: 27 inches in a normal year, falling on 25 days with 0.1 inch or more, the most in November (7.1 inches).
What is the rainiest month at Port Alcan?
July, with 2.71 in of precipitation in a normal year; the driest is March with 0.14 in.
What plant hardiness zone is Port Alcan in?
By the same method at the station, the coldest night of a typical year reaches −47°F (15 years, 1991-2020): zone 2a.
How late can frost come at Port Alcan?
In half of years the last 32°F night comes after May 28; in one year in ten it comes after June 10. Waiting until June 10 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Alaska climateThe statewide normals and every place in the state
- Tok (70 mi SE), AK11 miles from this station, 24.2°F a year
- Northway, AK37 miles from this station, 24.7°F a year
- Nabesna, AK65 miles from this station, 26.7°F a year
- Tok, AK81 miles from this station, 24.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made