Juneau, Alaska climate: Normal weather by month, frost dates and records
Juneau's normal year runs from 24°F January nights to 64°F July afternoons, with 67.0 inches of precipitation and 88 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.6°C, January lows of −5°C, July highs of 18°C, 1,702 mm of precipitation a year.
- NOAA stationJuneau Airport
- Station IDUSW00025309
- Location58.36°N 134.56°W
- Elevation16 ft (5 m)
- Population31,572
On October 23, the normal high in Juneau is 45°F and the normal low 35°F, and the chance of measurable rain or snow is 73%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Juneau.
- Jan 33° 24°
- Feb 36° 25°
- Mar 39° 27°
- Apr 49° 33°
- May 58° 40°
- Jun 62° 47°
- Jul 64° 50°
- Aug 63° 49°
- Sep 56° 44°
- Oct 47° 37°
- Nov 38° 29°
- Dec 35° 26°
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 Juneau each month?
July is the warmest month, with normal highs of 64°F; January the coldest, with normal lows of 24°F. The most precipitation falls in September (9.15 in), the least in April (3.47 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 24°F | 28.5°F | 6.02 | 24.5 | 20 | <1 | 23 | 7 h |
| February | 36°F | 25°F | 30.1°F | 4.31 | 16.7 | 17 | <1 | 21 | 9 h 20 min |
| March | 39°F | 27°F | 32.9°F | 3.67 | 12.4 | 18 | <1 | 22 | 11 h 40 min |
| April | 49°F | 33°F | 40.8°F | 3.47 | 1.2 | 17 | <1 | 13 | 14 h 20 min |
| May | 58°F | 40°F | 49.0°F | 3.51 | 0.0 | 16 | <1 | 2 | 16 h 40 min |
| June | 62°F | 47°F | 54.6°F | 3.82 | 0.0 | 17 | <1 | <1 | 18 h 10 min |
| July | 64°F | 50°F | 57.0°F | 5.14 | 0.0 | 19 | <1 | <1 | 17 h 40 min |
| August | 63°F | 49°F | 56.0°F | 6.41 | 0.0 | 19 | <1 | <1 | 15 h 30 min |
| September | 56°F | 44°F | 50.1°F | 9.15 | 0.0 | 22 | <1 | 1 | 13 h |
| October | 47°F | 37°F | 42.2°F | 8.42 | 0.9 | 23 | <1 | 8 | 10 h 20 min |
| November | 38°F | 29°F | 33.8°F | 6.54 | 13.8 | 21 | <1 | 17 | 8 h |
| December | 35°F | 26°F | 30.3°F | 6.53 | 18.1 | 21 | <1 | 21 | 6 h 30 min |
| Year (annual) | 48°F | 36°F | 42.1°F | 66.99 | 87.6 | 230 | <1 | 128 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −5°C | −1.9°C | 153 mm | 62 cm |
| February | 2°C | −4°C | −1.1°C | 109 mm | 42 cm |
| March | 4°C | −3°C | 0.5°C | 93 mm | 31 cm |
| April | 9°C | 0°C | 4.9°C | 88 mm | 3 cm |
| May | 14°C | 5°C | 9.4°C | 89 mm | 0 cm |
| June | 17°C | 8°C | 12.6°C | 97 mm | 0 cm |
| July | 18°C | 10°C | 13.9°C | 131 mm | 0 cm |
| August | 17°C | 10°C | 13.3°C | 163 mm | 0 cm |
| September | 13°C | 7°C | 10.1°C | 232 mm | 0 cm |
| October | 8°C | 3°C | 5.7°C | 214 mm | 2 cm |
| November | 3°C | −2°C | 1.0°C | 166 mm | 35 cm |
| December | 2°C | −3°C | −0.9°C | 166 mm | 46 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00025309; 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 Juneau?
No month's normal high reaches 65°F in Juneau: the warmest is July at 64°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 USW00025309.
When is the last frost in Juneau?
In Juneau, the last spring frost (32°F) comes after May 4 in half of years and after May 18 in one year in ten; the first autumn frost comes before October 3 in half of years and before September 18 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 41 year in 10 after May 18; 9 in 10 after April 23
- First autumn frost, half of years before
- October 31 year in 10 before September 18; 9 in 10 before October 20
NOAA puts the median frost-free season at 150 days, and the season without a hard freeze (28°F) at 181 days.
A hard freeze (28°F) comes after April 19 in half of springs and before October 18 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Juneau in zones 6a to 7a across its 2 ZIP code areas (6a in 99801, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Juneau's NOAA station is in zone 6b: the coldest night of a typical year reaches 0°F (30 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Alaska · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00025309; 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.
What hardiness zone is each Juneau ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Juneau's 2 ZIP code areas run from zone 6a to 7a: 1 in 6a and 1 in 7a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Juneau?
In a normal year in Juneau, a 90°F day is rare, 128 nights fall to 32°F or colder and 230 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
- 128a normal year
- Days that stay below freezing
- 39high of 32°F or less
- Days with 0.01 inch of precipitation
- 230a normal year
- Days with 1 inch of snow or more
- 23a normal year
The highest temperature in Juneau's official record (kept by the National Weather Service since 1943) is 90°F, on July 7, 1975; the lowest is −22°F, on January 12, 1972.
The wettest calendar year on that record is 2022, with 88.31 in; the snowiest season is 2006–07, with 197.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00025309; records: ACIS (NOAA Regional Climate Centers), NWS threaded record JNUthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Juneau, and how clear are its skies?
The summer (June-August) dew point averages 50°F. The muggiest month is July, with an average dew point of 52°F; the driest air comes in February (23°F). April is the windiest month (8.2 mph on average), and February has the most clear or nearly clear hours (30%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 25°F | 84% | 79% | 7.4 mph | 16% | 70% |
| February | 23°F | 76% | 64% | 7.4 mph | 30% | 52% |
| March | 30°F | 76% | 61% | 7.4 mph | 21% | 57% |
| April | 36°F | 72% | 55% | 8.2 mph | 23% | 55% |
| May | 44°F | 74% | 58% | 7.2 mph | 15% | 57% |
| June | 49°F | 77% | 63% | 6.7 mph | 12% | 62% |
| July | 52°F | 82% | 70% | 6.4 mph | 12% | 65% |
| August | 49°F | 87% | 76% | 7.1 mph | 9% | 70% |
| September | 44°F | 89% | 79% | 7.6 mph | 9% | 73% |
| October | 34°F | 87% | 82% | 7.2 mph | 11% | 73% |
| November | 28°F | 85% | 83% | 8.0 mph | 12% | 71% |
| December | 25°F | 84% | 83% | 7.3 mph | 17% | 69% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00025309. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Juneau?
Over a year 57% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Juneau, 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 Juneau need?
A normal year in Juneau brings 8,335 heating degree days, 55% more than the median U.S. place (5,373), and 3 cooling degree days, 100% 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 646 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,133 | 0 |
| February | 976 | 0 |
| March | 995 | 0 |
| April | 726 | 0 |
| May | 498 | 0 |
| June | 313 | 1 |
| July | 248 | 1 |
| August | 280 | 1 |
| September | 447 | 0 |
| October | 707 | 0 |
| November | 938 | 0 |
| December | 1,076 | 0 |
| Year (annual) | 8,335 | 3 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00025309. 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.
Has Juneau been warmer than normal lately?
2024 averaged 42.5°F, 0.4°F above the 1991-2020 normal of 42.1°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 41.7°F | −0.4°F | 76.53 | 137.0 |
| 2022 | 43.0°F | +0.9°F | 88.31 | 65.1 |
| 2023 | 44.0°F | +1.9°F | 77.11 | 86.3 |
| 2024 | 42.5°F | +0.4°F | 72.06 | 125.5 |
Over 99 complete years from 1899 to 2025, the station's annual mean temperature rose at a fitted 1.9°F per century (+0.10°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00025309; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Juneau's climate compare?
Juneau is warmer than 68 of the other 84 places with their own NOAA record in Alaska, and wetter than 55. Across the 7,247 U.S. stations with normals, its annual mean of 42.1°F is warmer than 10%.
In the Köppen classification computed from these normals, Juneau is Dfb: continental, no dry season, warm 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.
What do Juneau's other NOAA stations record?
4 more NOAA stations keep 1991-2020 normals in or near Juneau. This page uses Juneau Airport; the others differ by site and elevation, and the linked ones have pages of their own:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Juneau Downtown USC00504094 | 7 mi SE | 50 ft | 43.5°F | 27°F | 63°F | 89.6 | – | April 20 |
| Juneau Forecast Office USC00504103 | 3 mi N | 106 ft | 40.3°F | 21°F | 62°F | 81.3 | – | May 9 |
| Juneau Lena Point USC00504107 | 8 mi W | 35 ft | 44.0°F | 27°F | 64°F | 62.3 | 77 | April 11 |
| Juneau Mile 17 USC00504109 | 7 mi NW | 245 ft | 42.5°F | 25°F | 63°F | – | – | April 29 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Juneau's climate
What is the coldest month in Juneau?
January, with a normal high of 33°F and a normal low of 24°F. The warmest is July (64°F by day, 50°F at night).
Does it snow in Juneau?
Yes: 88 inches in a normal year, falling on 44 days with 0.1 inch or more, the most in January (24.5 inches).
What is the rainiest month in Juneau?
September, with 9.15 in of precipitation in a normal year; the driest is April with 3.47 in.
What plant hardiness zone is Juneau in?
The USDA's 2023 map puts Juneau in zones 6a to 7a across its 2 ZIP code areas (6a in 99801, the largest). By the same method at Juneau's NOAA station, the coldest night of a typical year reaches 0°F (30 years, 1991-2020): zone 6b.
How late can frost come in Juneau?
In half of years the last 32°F night comes after May 4; in one year in ten it comes after May 18. Waiting until May 18 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Juneau in OctoberThis month day by day, its records and recent years
- Alaska climateThe statewide normals and every place in the state
- Auke Bay, AK3 miles from this station, 42.5°F a year
- Eaglecrest Base, AK6 miles from this station, 38.0°F a year
- Juneau Downtown, AK7 miles from this station, 43.5°F a year
- Annex Creek, AK17 miles from this station, 39.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made