Juneau climate — normals and trends
Juneau (United States) has a subarctic climate (Dfc) under the Köppen-Geiger classification. Its mean annual temperature is 2.3 °C and it receives 2,609 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (11.8 °C on average) and the coldest is January (-6.9 °C). Rainfall peaks in October.
Juneau averages 177 frost days, 0 hot days (≥ 30 °C) and 229 rainy days per year.
Juneau has warmed by +3.8 °C between 1940 and 2025, or +0.44 °C per decade. This trend is statistically significant.
The number of frost days there went from about 207 to 147 per year over the period.
The hottest day of the period reached 29.2 °C (on 12 August 1990) and the coldest -32.6 °C (on 15 December 1964).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
JuneauAlaska
- coords
- 58.30°, -134.42°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
2.3°C
Average daily high
5.0°C
Average daily low
-0.6°C
Annual rainfall
2,609mm
Sunshine / day
6.1h
Mean relative humidity
80%
Average peak wind
10.5km/h
Seasonal range
18.7°C
Frost days (< 0 °C)
177 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
229 d/yr
Annual snowfall
775.2 cm
Average feels-like high
2.4 °C
Average feels-like low
-3.9 °C
Average peak gust
37.0 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
9.1 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+3.8 °C
since 1940
+0.4 °C per decade · r² = 0.57 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
29.2 °C
12 August 1990
Coldest day
-32.6 °C
15 December 1964
Wettest day
111 mm
25 September 1996
Windiest day
35.2 km/h
28 November 1968
Strongest gust
143.6 km/h
28 November 1968
Hottest feels-like
32.3 °C
12 August 1990
Coldest feels-like
-38.6 °C
14 December 1964
Snowiest day
42.7 cm
27 January 2000
Sunniest day
17.9 h
21 June 2025
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 0.7 °C | +5.5 °C | 327 mm | +89 mm |
| Feb | -2.0 °C | +0.7 °C | 141 mm | -49 mm |
| Mar | 3.1 °C | +3.0 °C | 150 mm | -39 mm |
| Apr | 5.1 °C | +0.9 °C | 247 mm | +94 mm |
| May | 6.4 °C | -1.9 °C | 282 mm | +139 mm |
| Jun | 13.2 °C | +0.8 °C | 176 mm | +49 mm |
| Jul | 16.2 °C | +1.3 °C | 140 mm | -25 mm |
| Aug | 17.0 °C | +2.2 °C | 200 mm | -20 mm |
| Sep | 13.6 °C | +2.0 °C | 423 mm | +112 mm |
| Oct | 7.6 °C | +2.2 °C | 360 mm | +5 mm |
| Nov | 1.8 °C | +2.6 °C | 288 mm | +24 mm |
| Dec | -8.3 °C | -4.9 °C | 276 mm | +23 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Juneau?
Juneau has a subarctic climate (Köppen Dfc). Over 1940-2025, the average annual temperature is 2.3 °C and it receives 2,609 mm of precipitation per year.
What is the hottest day ever recorded in Juneau?
The hottest day measured in Juneau between 1940 and 2025 was 12 August 1990, reaching 29.2 °C.
What is the coldest day in Juneau?
The coldest day measured in Juneau between 1940 and 2025 was 15 December 1964, at -32.6 °C.
Does it snow in Juneau?
Yes. Juneau gets on average 775.2 cm of snow per year and has around 177 frost days.
Has the climate of Juneau warmed?
Yes: Juneau warmed by +3.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Juneau?
The wettest day measured in Juneau between 1940 and 2025 was 25 September 1996, with 111 mm of rain in 24 hours.
What was the windiest day in Juneau?
The windiest day measured in Juneau between 1940 and 2025 was 28 November 1968, with winds reaching 35.2 km/h.
What is the warmest month in Juneau?
The warmest month in Juneau is July (11.8 °C on average); the coldest is January (-6.9 °C).
How much does it rain in Juneau?
Juneau receives on average 2,609 mm of precipitation per year, spread over about 229 rainy days.
Is it sunny in Juneau?
Juneau gets on average 6.1 hours of sunshine per day, roughly 2,227 hours per year over 1940-2025.
What is the biggest single-day snowfall in Juneau?
The heaviest 24-hour snowfall measured in Juneau between 1940 and 2025 was 27 January 2000, with 42.7 cm.
Are there tropical nights in Juneau?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Juneau.
What was the most extreme apparent temperature in Juneau?
In Juneau, between 1940 and 2025, the highest apparent temperature reached 32.3 °C on 12 August 1990, and the lowest was -38.6 °C on 14 December 1964.
Compare Juneau with another city
Pick a second city: its normals will be set against these, indicator by indicator.