Gustavus, Alaska climate: Normal weather by month, frost dates and records
Gustavus's normal year runs from 22°F January nights to 63°F July afternoons, with 58.7 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 4.8°C, January lows of −6°C, July highs of 17°C, 1,491 mm of precipitation a year.
- NOAA stationGustavus (2 mi NE)
- Station IDUSW00025380
- Location58.43°N 135.69°W
- Elevation20 ft (6 m)
- Population623
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Gustavus.
- Jan 33° 22°
- Feb 37° 23°
- Mar 40° 24°
- Apr 49° 29°
- May 57° 35°
- Jun 62° 42°
- Jul 63° 47°
- Aug 63° 46°
- Sep 56° 41°
- Oct 48° 34°
- Nov 39° 28°
- Dec 35° 24°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Gustavus each month?
July is the warmest month, with normal highs of 63°F; January the coldest, with normal lows of 22°F. The most precipitation falls in October (8.25 in), the least in June (2.50 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 33°F | 22°F | 27.6°F | 4.94 | – | <1 | 23 | 7 h |
| February | 37°F | 23°F | 30.0°F | 3.62 | – | <1 | 22 | 9 h 20 min |
| March | 40°F | 24°F | 31.7°F | 3.50 | – | <1 | 25 | 11 h 40 min |
| April | 49°F | 29°F | 38.8°F | 2.80 | – | <1 | 19 | 14 h 20 min |
| May | 57°F | 35°F | 46.0°F | 2.75 | – | <1 | 11 | 16 h 40 min |
| June | 62°F | 42°F | 52.4°F | 2.50 | – | <1 | 1 | 18 h 20 min |
| July | 63°F | 47°F | 55.0°F | 4.19 | – | <1 | <1 | 17 h 40 min |
| August | 63°F | 46°F | 54.3°F | 5.69 | – | <1 | 1 | 15 h 30 min |
| September | 56°F | 41°F | 48.7°F | 7.64 | – | <1 | 6 | 13 h |
| October | 48°F | 34°F | 40.8°F | 8.25 | – | <1 | 13 | 10 h 20 min |
| November | 39°F | 28°F | 33.3°F | 6.31 | – | <1 | 20 | 8 h |
| December | 35°F | 24°F | 29.5°F | 6.50 | – | <1 | 21 | 6 h 20 min |
| Year (annual) | 48°F | 33°F | 40.6°F | 58.69 | – | <1 | 163 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 1°C | −6°C | −2.4°C | 125 mm |
| February | 3°C | −5°C | −1.1°C | 92 mm |
| March | 4°C | −5°C | −0.2°C | 89 mm |
| April | 9°C | −2°C | 3.8°C | 71 mm |
| May | 14°C | 2°C | 7.8°C | 70 mm |
| June | 17°C | 6°C | 11.3°C | 64 mm |
| July | 17°C | 8°C | 12.8°C | 106 mm |
| August | 17°C | 8°C | 12.4°C | 145 mm |
| September | 14°C | 5°C | 9.3°C | 194 mm |
| October | 9°C | 1°C | 4.9°C | 210 mm |
| November | 4°C | −2°C | 0.7°C | 160 mm |
| December | 2°C | −4°C | −1.4°C | 165 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Gustavus's own co-op station Gustavus station does: 72 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00025380; 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.
When is the best weather to visit Gustavus?
No month's normal high reaches 65°F in Gustavus: the warmest is July at 63°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 USW00025380.
When is the last frost in Gustavus?
In Gustavus, the last spring frost (32°F) comes after May 28 in half of years and after June 12 in one year in ten; the first autumn frost comes before September 25 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 281 year in 10 after June 12; 9 in 10 after May 12
- First autumn frost, half of years before
- September 251 year in 10 before August 29; 9 in 10 before October 11
NOAA puts the median frost-free season at 116 days, and the season without a hard freeze (28°F) at 143 days.
A hard freeze (28°F) comes after May 13 in half of springs and before October 5 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Gustavus in zone 7a in ZIP code 99826.
Frost dates for every NOAA station in Alaska · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00025380; 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 in Gustavus?
In a normal year in Gustavus, a 90°F day is rare and 163 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
- 163a normal year
- Days that stay below freezing
- 31high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USW00025380.
How sunny is Gustavus?
Over a year 57% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Gustavus, 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 much heating and cooling does Gustavus need?
A normal year in Gustavus brings 8,871 heating degree days, 65% 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 421 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,161 | 0 |
| February | 982 | 0 |
| March | 1,034 | 0 |
| April | 786 | 0 |
| May | 589 | 0 |
| June | 380 | 0 |
| July | 312 | 0 |
| August | 333 | 0 |
| September | 491 | 0 |
| October | 752 | 0 |
| November | 953 | 0 |
| December | 1,101 | 0 |
| Year (annual) | 8,871 | 0 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00025380. 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 Gustavus's climate compare?
Gustavus is warmer than 64 of the other 84 places with their own NOAA record in Alaska, and wetter than 53. Across the 7,247 U.S. stations with normals, its annual mean of 40.6°F is warmer than 7%.
In the Köppen classification computed from these normals, Gustavus 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 Gustavus share this climate record?
Excursion Inlet 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.
- Excursion Inlet, AK66 people · 12 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Gustavus's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Gustavus. This page uses Gustavus (2 mi NE); the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Gustavus station USW00025322 | 1 mi SW | 40 ft | 40.1°F | 21°F | 63°F | 62.3 | 72 | May 30 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Gustavus's climate
What is the coldest month in Gustavus?
January, with a normal high of 33°F and a normal low of 22°F. The warmest is July (63°F by day, 47°F at night).
Does it snow in Gustavus?
Yes. NOAA publishes no 1991-2020 snowfall normal for Gustavus's NOAA station; Gustavus's own co-op station Gustavus station records 72 inches of snow in a normal year.
What is the rainiest month in Gustavus?
October, with 8.25 in of precipitation in a normal year; the driest is June with 2.50 in.
What plant hardiness zone is Gustavus in?
The USDA's 2023 map puts Gustavus in zone 7a in ZIP code 99826.
How late can frost come in Gustavus?
In half of years the last 32°F night comes after May 28; in one year in ten it comes after June 12. Waiting until June 12 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Alaska climateThe statewide normals and every place in the state
- Glacier Bay, AK7 miles from this station, 40.9°F a year
- Hoonah, AK24 miles from this station, 43.1°F a year
- Elfin Cove, AK29 miles from this station, 42.8°F a year
- Pelican, AK38 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