Juneau Downtown, Alaska climate: Climate normals at a NOAA weather station
Juneau Downtown's normal year runs from 27°F January nights to 63°F July afternoons, with 89.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 6.4°C, January lows of −3°C, July highs of 17°C, 2,276 mm of precipitation a year.
- NOAA stationJuneau Downtown
- Station IDUSC00504094
- Location58.30°N 134.41°W
- Elevation50 ft (15 m)
On October 23, the normal high in Juneau Downtown is 46°F and the normal low 37°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Juneau Downtown.
- Jan 34° 27°
- Feb 37° 28°
- Mar 39° 30°
- Apr 49° 36°
- May 57° 43°
- Jun 62° 49°
- Jul 63° 52°
- Aug 62° 51°
- Sep 56° 46°
- Oct 48° 39°
- Nov 40° 32°
- Dec 36° 29°
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 Juneau Downtown each month?
July is the warmest month, with normal highs of 63°F; January the coldest, with normal lows of 27°F. The most precipitation falls in September (12.71 in), the least in April (4.76 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 34°F | 27°F | 30.3°F | 5.88 | – | <1 | 22 | 7 h |
| February | 37°F | 28°F | 32.2°F | 5.16 | – | <1 | 19 | 9 h 20 min |
| March | 39°F | 30°F | 34.5°F | 6.17 | – | <1 | 20 | 11 h 40 min |
| April | 49°F | 36°F | 42.2°F | 4.76 | – | <1 | 6 | 14 h 20 min |
| May | 57°F | 43°F | 50.2°F | 5.09 | – | <1 | <1 | 16 h 40 min |
| June | 62°F | 49°F | 55.6°F | 4.90 | – | <1 | <1 | 18 h 10 min |
| July | 63°F | 52°F | 57.3°F | 6.21 | – | <1 | <1 | 17 h 40 min |
| August | 62°F | 51°F | 56.7°F | 7.76 | – | <1 | <1 | 15 h 30 min |
| September | 56°F | 46°F | 51.1°F | 12.71 | – | <1 | <1 | 13 h |
| October | 48°F | 39°F | 43.7°F | 12.27 | – | <1 | 4 | 10 h 20 min |
| November | 40°F | 32°F | 36.0°F | 8.75 | – | <1 | 14 | 8 h |
| December | 36°F | 29°F | 32.5°F | 9.93 | – | <1 | 19 | 6 h 30 min |
| Year (annual) | 49°F | 38°F | 43.5°F | 89.59 | – | <1 | 105 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 1°C | −3°C | −0.9°C | 149 mm |
| February | 3°C | −2°C | 0.1°C | 131 mm |
| March | 4°C | −1°C | 1.4°C | 157 mm |
| April | 9°C | 2°C | 5.7°C | 121 mm |
| May | 14°C | 6°C | 10.1°C | 129 mm |
| June | 17°C | 9°C | 13.1°C | 124 mm |
| July | 17°C | 11°C | 14.1°C | 158 mm |
| August | 17°C | 11°C | 13.7°C | 197 mm |
| September | 13°C | 8°C | 10.6°C | 323 mm |
| October | 9°C | 4°C | 6.5°C | 312 mm |
| November | 4°C | 0°C | 2.2°C | 222 mm |
| December | 2°C | −2°C | 0.3°C | 252 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Juneau (7 miles away), gets 88 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00504094; 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 Juneau Downtown?
No month's normal high reaches 65°F in Juneau Downtown: 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 USC00504094.
When is the last frost at Juneau Downtown?
In Juneau Downtown, the last spring frost (32°F) comes after April 20 in half of years and after May 5 in one year in ten; the first autumn frost comes before October 22 in half of years and before October 5 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
- April 201 year in 10 after May 5; 9 in 10 after April 5
- First autumn frost, half of years before
- October 221 year in 10 before October 5; 9 in 10 before November 7
NOAA puts the median frost-free season at 183 days, and the season without a hard freeze (28°F) at 218 days.
A hard freeze (28°F) comes after April 2 in half of springs and before November 8 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Juneau Downtown in zone 7a in ZIP code 99824, 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 USC00504094; 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 Juneau Downtown?
In a normal year in Juneau Downtown, a 90°F day is rare and 105 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
- 105a normal year
- Days that stay below freezing
- 28high of 32°F or less
The highest temperature in this station's record (since 1890) is 89°F, on July 26, 1915; the lowest is −15°F, on January 20, 1916.
The wettest calendar year on that record is 1939, with 119.48 in; the snowiest season is 1955–56, with 166.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00504094; records: ACIS (NOAA Regional Climate Centers), station USC00504094. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Juneau Downtown?
Over a year 57% of the sunlight that would reach the ground under clear skies gets through the clouds at Juneau Downtown, 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 Juneau Downtown record?
A normal year at Juneau Downtown brings 7,827 heating degree days, 46% more than the median U.S. place (5,373), and 12 cooling degree days, 99% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 750 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,076 | 0 |
| February | 918 | 0 |
| March | 946 | 0 |
| April | 684 | 0 |
| May | 459 | 1 |
| June | 286 | 4 |
| July | 242 | 5 |
| August | 260 | 2 |
| September | 417 | 0 |
| October | 662 | 0 |
| November | 870 | 0 |
| December | 1,008 | 0 |
| Year (annual) | 7,827 | 12 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00504094. 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 Juneau Downtown been warmer than normal?
Over 79 complete years from 1890 to 2020, the station's annual mean temperature rose at a fitted 2.3°F per century (+0.13°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Juneau Downtown's climate compare?
Juneau Downtown is warmer than 76 of the 85 places with their own NOAA record in Alaska, and wetter than 64. Across the 7,247 U.S. stations with normals, its annual mean of 43.5°F is warmer than 14%.
In the Köppen classification computed from these normals, Juneau Downtown 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.
Questions about Juneau Downtown's climate
What is the coldest month at Juneau Downtown?
January, with a normal high of 34°F and a normal low of 27°F. The warmest is July (63°F by day, 52°F at night).
Does it snow at Juneau Downtown?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Juneau (7 miles away), records 88 inches of snow in a normal year.
What is the rainiest month at Juneau Downtown?
September, with 12.71 in of precipitation in a normal year; the driest is April with 4.76 in.
What plant hardiness zone is Juneau Downtown in?
The USDA's 2023 map puts Juneau Downtown in zone 7a in ZIP code 99824, the nearest ZIP area.
How late can frost come at Juneau Downtown?
In half of years the last 32°F night comes after April 20; in one year in ten it comes after May 5. Waiting until May 5 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Alaska climateThe statewide normals and every place in the state
- Eaglecrest Base, AK4 miles from this station, 38.0°F a year
- Juneau, AK7 miles from this station, 42.1°F a year
- Auke Bay, AK10 miles from this station, 42.5°F a year
- Annex Creek, AK11 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