Glacier Bay, Alaska climate: Climate normals at a NOAA weather station
Glacier Bay's normal year runs from 26°F January nights to 61°F July afternoons, with 72.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.9°C, January lows of −4°C, July highs of 16°C, 1,844 mm of precipitation a year.
- NOAA stationGlacier Bay
- Station IDUSC00503294
- Location58.46°N 135.87°W
- Elevation45 ft (14 m)
On October 23, the normal high in Glacier Bay is 43°F and the normal low 35°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Glacier Bay.
- Jan 32° 26°
- Feb 34° 26°
- Mar 37° 28°
- Apr 46° 33°
- May 54° 39°
- Jun 59° 45°
- Jul 61° 49°
- Aug 60° 48°
- Sep 54° 43°
- Oct 45° 37°
- Nov 37° 30°
- Dec 33° 27°
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 Glacier Bay each month?
July is the warmest month, with normal highs of 61°F; January the coldest, with normal lows of 26°F. The most precipitation falls in October (10.16 in), the least in June (2.83 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 32°F | 26°F | 28.5°F | 6.71 | – | <1 | 27 | 7 h |
| February | 34°F | 26°F | 29.7°F | 4.76 | – | <1 | 25 | 9 h 20 min |
| March | 37°F | 28°F | 32.3°F | 4.35 | – | <1 | 26 | 11 h 40 min |
| April | 46°F | 33°F | 39.3°F | 3.38 | – | <1 | 16 | 14 h 20 min |
| May | 54°F | 39°F | 46.6°F | 3.06 | – | <1 | 3 | 16 h 40 min |
| June | 59°F | 45°F | 52.2°F | 2.83 | – | <1 | <1 | 18 h 20 min |
| July | 61°F | 49°F | 54.6°F | 4.76 | – | <1 | <1 | 17 h 40 min |
| August | 60°F | 48°F | 54.0°F | 5.97 | – | <1 | <1 | 15 h 30 min |
| September | 54°F | 43°F | 48.4°F | 9.16 | – | <1 | 1 | 13 h |
| October | 45°F | 37°F | 41.0°F | 10.16 | – | <1 | 7 | 10 h 20 min |
| November | 37°F | 30°F | 33.4°F | 8.51 | – | <1 | 20 | 7 h 50 min |
| December | 33°F | 27°F | 30.3°F | 8.95 | – | <1 | 26 | 6 h 20 min |
| Year (annual) | 46°F | 36°F | 40.9°F | 72.60 | – | <1 | 149 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 0°C | −4°C | −1.9°C | 170 mm |
| February | 1°C | −3°C | −1.3°C | 121 mm |
| March | 3°C | −2°C | 0.2°C | 110 mm |
| April | 8°C | 1°C | 4.1°C | 86 mm |
| May | 12°C | 4°C | 8.1°C | 78 mm |
| June | 15°C | 7°C | 11.2°C | 72 mm |
| July | 16°C | 9°C | 12.6°C | 121 mm |
| August | 16°C | 9°C | 12.2°C | 152 mm |
| September | 12°C | 6°C | 9.1°C | 233 mm |
| October | 7°C | 3°C | 5.0°C | 258 mm |
| November | 3°C | −1°C | 0.8°C | 216 mm |
| December | 1°C | −3°C | −0.9°C | 227 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Gustavus station (7 miles away), gets 72 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00503294; 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 Glacier Bay?
No month's normal high reaches 65°F in Glacier Bay: the warmest is July at 61°F.
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 USC00503294.
When is the last frost at Glacier Bay?
In Glacier Bay, the last spring frost (32°F) comes after May 6 in half of years and after May 26 in one year in ten; the first autumn frost comes before October 10 in half of years and before September 19 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 61 year in 10 after May 26; 9 in 10 after April 22
- First autumn frost, half of years before
- October 101 year in 10 before September 19; 9 in 10 before October 28
NOAA puts the median frost-free season at 154 days, and the season without a hard freeze (28°F) at 186 days.
A hard freeze (28°F) comes after April 20 in half of springs and before October 28 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Glacier Bay in zone 7a in ZIP code 99826, 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 USC00503294; 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 Glacier Bay?
In a normal year in Glacier Bay, a 90°F day is rare and 149 nights fall to 32°F or colder.
- 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
- 149a normal year
- Days that stay below freezing
- 35high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00503294.
How sunny is it at Glacier Bay?
Over a year 57% of the sunlight that would reach the ground under clear skies gets through the clouds at Glacier Bay, 2.4 kWh per square metre a day. May is the sunniest month (62%) and January the cloudiest (46%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 46% | 0.3 |
| February | 53% | 1.0 |
| March | 56% | 2.1 |
| April | 60% | 3.6 |
| May | 62% | 4.7 |
| June | 59% | 4.9 |
| July | 56% | 4.3 |
| August | 56% | 3.5 |
| September | 53% | 2.2 |
| October | 49% | 1.1 |
| November | 47% | 0.5 |
| December | 47% | 0.2 |
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 Glacier Bay record?
A normal year at Glacier Bay brings 8,788 heating degree days, 64% more than the median U.S. place (5,373), and 0 cooling degree days, 100% fewer than the median (908). Twelve months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 397 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,130 | 0 |
| February | 987 | 0 |
| March | 1,014 | 0 |
| April | 773 | 0 |
| May | 570 | 0 |
| June | 384 | 0 |
| July | 323 | 0 |
| August | 343 | 0 |
| September | 498 | 0 |
| October | 744 | 0 |
| November | 947 | 0 |
| December | 1,077 | 0 |
| Year (annual) | 8,788 | 0 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00503294. 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.
How does Glacier Bay's climate compare?
Glacier Bay is warmer than 65 of the 85 places with their own NOAA record in Alaska, and wetter than 58. Across the 7,247 U.S. stations with normals, its annual mean of 40.9°F is warmer than 7%.
In the Köppen classification computed from these normals, Glacier Bay 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 Glacier Bay's climate
What is the coldest month at Glacier Bay?
January, with a normal high of 32°F and a normal low of 26°F. The warmest is July (61°F by day, 49°F at night).
Does it snow at Glacier Bay?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Gustavus station (7 miles away), records 72 inches of snow in a normal year.
What is the rainiest month at Glacier Bay?
October, with 10.16 in of precipitation in a normal year; the driest is June with 2.83 in.
What plant hardiness zone is Glacier Bay in?
The USDA's 2023 map puts Glacier Bay in zone 7a in ZIP code 99826, the nearest ZIP area.
How late can frost come at Glacier Bay?
In half of years the last 32°F night comes after May 6; in one year in ten it comes after May 26. Waiting until May 26 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Alaska climateThe statewide normals and every place in the state
- Gustavus, AK7 miles from this station, 40.6°F a year
- Elfin Cove, AK25 miles from this station, 42.8°F a year
- Hoonah, AK29 miles from this station, 43.1°F a year
- Pelican, AK37 miles from this station, 42.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made