Climate and monthly weather forecastJuneau, AK
Climate and monthly weather forecast
The climate of Juneau
Located in the northern part of the United States, Juneau, Alaska, falls under the Dfc category as per the Köppen climate classification. This signifies a subarctic climate with extremely harsh winters, no dry season and a rather cool summer.High temperatures shift within the span of the year from 25.7°F (-3.5°C) to 55.8°F (13.2°C) whereas the lows fluctuate between a frigid 17.1°F (-8.3°C) and a modest 45.1°F (7.3°C). The sizeable stretch from 4.13" (105mm) to 9.88" (251mm) in rainfall volume demonstrates a notable wet season. Moreover, snowfall incidents extend significantly from zero days in May to July to around 21.8 days in December, with snowfall depths ranging from zero inches to a phenomenal 62.8" (1595mm).
The amount of daylight in Juneau varies from 6.5 hours in December to an astronomical 18.2 hours in June, alongside sunshine duration amid the entire year from 2.6 to 5.7 hours. Additionally, the UV index peaks at 3 between May and July, signifying a moderate risk from unprotected exposure to the Sun. The climate of Juneau »
The best time to visit Juneau
Reviewing the climate figures, the optimal months to travel to Juneau would be from May to July. The town experiences considerably mild temperatures during these periods, with highs soaring between 47.5°F (8.6°C) and 55.8°F (13.2°C). Yet, it is essential to carry warm clothing as the temperatures plummet to lows between 35.2°F (1.8°C) to 45.1°F (7.3°C) at night. These months also register lower precipitation, descending from 4.13" (105mm) to 4.61" (117mm), and daylight hours peak at around 16.8 to 18.2 hours. The best time to visit Juneau »The worst time to visit Juneau
The winter months from November to January arguably present the least hospitable conditions to visit Juneau. During these months, the temperature drops to lows between 19°F (-7.2°C) to 23.7°F (-4.6°C) and rarely ascends above a chilly 29.8°F (-1.2°C) to 25.7°F (-3.5°C). Snowfall also escalates, reaching up to 62.8" (1595mm) during December while facing snowfall events for nearly 20 days each month. Coupled with the limited daylight of a mere 6.5 to 7.9 hours, these considerations make outdoor activities greatly unfavorable. The worst time to visit Juneau »Spring weather in Juneau
Spring in Juneau, which spans from March to May, welcomes a gradual rise in temperature from 29.5°F (-1.4°C) to 47.5°F (8.6°C) in the daytime, while the nights are substantially cold with lows between 26.4°F (-3.1°C) to 35.2°F (1.8°C). Rainfall is prominent across these months, with averages ranging from 6.02" (153mm) to 4.13" (105mm) with about 13 to 18 rainfall days. Light snowfall in March gives way to completely snow-free conditions by May. Visitors also witness extended hours of daylight from 11.9 hours to 16.8 hours. Spring weather in Juneau »Summer weather in Juneau
Juneau's summer from June to August offers temperatures between 51.6°F (10.9°C) to 55.8°F (13.2°C) at the peak of the day, dropping to a colder 40.6°F (4.8°C) to 45.1°F (7.3°C) in the late hours. Rainfall is moderate during this time, with averages between 4.53" (115mm) to 7.56" (192mm), and there is no incident of snowfall across these months. Daylight is at its peak, with the city basking in the sun for around 17.4 to 18.2 hours, urging explorers to squeeze every drop of Alaskan summer they can. Summer weather in Juneau »Autumn weather in Juneau
Heading into autumn, from September through November, Juneau cools down significantly as daytime temperatures fall from 48.2°F (9°C) to 29.8°F (-1.2°C) and night temperatures decline to a chilly 23.7°F (-4.6°C) to 39.7°F (4.3°C). Rainfall peaks at 9.88" (251mm), with about 20 to 21 days of rain per month. The first signs of snow appear in November, with 9.29" (236mm) of snowfall. The sunlight contracts, with daylight duration shrinking from 12.8 hours to 7.9 hours. Autumn weather in Juneau »Winter weather in Juneau
Winter in Juneau kicks off in December and runs through February, recording frigid temperatures from 25.7°F (-3.5°C) to 18.7°F (-7.4°C) during the day, and falling to a harsh 19°F (-7.2°C) at night. December experiences the peak snowfall at a staggering 62.8" (1595mm). Rainfall also remains high, fluctuating between 8.98" (228mm) to 9.76" (248mm), with around 20 days of precipitation per month. As winter sets in, daylight dwindles to about 6.5 to 7.3 hours on average, and sunlight is scarce with just 2.9 to 2.8 hours. Winter weather in Juneau »Weather in January
The year in Juneau, Alaska begins with cold and snowy winter days. January brings the heaviest snowfall of the year, reaching as high as 58.74" (1492mm), and the lowest average temperatures, ranging between 18.7°F (-7.4°C) and 25.7°F (-3.5°C). Weather in January »Weather in February
Transitions in Alaska's weather patterns start to become apparent in February. Snowfall decreases compared to January, but it is still a prominent feature of the season. With a subtle rise in temperature, the days become slightly warmer, offering residents a hint of the coming spring. Weather in February »Weather in March
As March unfolds in Juneau, winter loosens its hold and gradual signs of the upcoming spring begin to appear. There is a noticeable rise in temperature and a significantly reduced snowfall to 42.28" (1074mm), compared to February's snowy days. Weather in March »Weather in April
April marks a clear shift in weather in Juneau, as winter officially gives way to spring. The landscape transforms as the snow retreats, reduced to just 29.45" (748mm). Along with this, a noticeable rise in temperature induces a freshness in the air and the environment. Weather in April »Weather in May
As the peak of spring arrives in May, the weather becomes noticeably milder in Juneau. The last traces of snow vanish, replaced by sporadic rain showers, particularly as the month progresses. As the temperature continues to rise, the landscape bursts with the freshness of the budding greenery. Weather in May »Weather in June
June is the onset of summer in Juneau, and it comes with a clear upward shift in temperatures. Snow is a thing of the past, giving way to moderate rainfall. As the city drifts into the warmest season, there are more hours of daylight than any other month. Weather in June »Weather in July
July brings classic summer weather to Juneau; it is the hottest month with temperatures reaching up to 55.8°F (13.2°C). The days are long and sunny, and the sea warms to 50.7°F (10.4°C), the highest of the year. Despite the heat, the humidity remains comfortable, making July a perfect time for picnics and hikes under the blue, sunny skies. Weather in July »Weather in August
August continues the summer season in Juneau, though temperatures mildly decrease compared to July. Regardless, it is an exceptionally pleasant time, with plenty of sunshine and warmth. The sea temperature remains consistent, preserving options for various water activities. Weather in August »Weather in September
September marks the transition from summer to fall in Juneau. Temperatures start to drop once again, indicating upcoming changes in the weather. The warmer weather fades, and the rain starts to increase, reaching an average of 8.27" (210mm). Weather in September »Weather in October
October is the definitive arrival of fall in Juneau, characterized by lower temperatures and a significant increase in rainfall. Damp and chilly, it brings the first sign of the approaching winter as snow begins to fall, registering an average of 9.29" (236mm). Weather in October »Weather in November
As the late fall sets in during November, Juneau's weather turns considerably cold and wet. The arrival of heavy snowfall at 35.75" (908mm) contrasts with the receding rainfall. The noticeable drop in temperature and short daylight hours strongly hint at the approaching winter. Weather in November »Weather in December
December welcomes winter back to Juneau with cold temperatures and heavy snowfall. An average accumulation of 62.8" (1595mm) of snow, the highest after January, blankets the city. While temperatures mirror those in January, daylight hours are at their shortest for the year. Weather in December »Updated: Aug 5, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
The coldest period, with an average high-temperature of 25.7°F (-3.5°C), falls in January and December.
With an average relative humidity of 92%, January is the most humid month.
Throughout the year, there are 172.4 rainfall days, and 85.87" (2181mm) of precipitation is accumulated.
Months with snowfall in Juneau, Alaska, are January through May, October through December.
In Juneau, during the entire year, snow falls for 126.6 days and aggregates up to 290.12" (7369mm) of snow.
The months with the lowest UV index are January, April, October through December, with an average maximum UV index of 1.
March is the month with the coldest seawater, with an average ocean temperature of 40.5°F (4.7°C).
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from AKST to AKDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from AKDT to AKST.
With an average relative humidity of 86%, May is the least humid month.
May is the month with the least rainfall in Juneau. Rain falls for 18.5 days and accumulates 4.13" (105mm) of precipitation.
May and July, with an average maximum UV index of 3, are months with the highest UV index.
June through September are months without snowfall.
The month with the longest days is June, with an average of 18h and 12min of daylight.
The month with the most sunshine is June, with an average of 6.4h of sunshine.
Juneau's July weather, marked by an average high temperature of 55.8°F (13.2°C) and an average low temperature of 45.1°F (7.3°C), is the warmest in the year.
With an average ocean temperature of 53.4°F (11.9°C), August is the month with the warmest seawater.
The month with the most rainfall is October, when the rain falls for 20 days and typically aggregates up to 9.88" (251mm) of precipitation.
November has the least sunshine of the year, with an average of 2.6h of sunshine.
December is the month with the most snowfall. Snow falls for 21.8 days and accumulates 62.8" (1595mm) of snow.
With an average of 6h and 30min of daylight, December has the shortest days of the year.
Average temperature
Juneau, AK
The warmest month (with the highest average high temperature) is July (55.8°F).
The months with the lowest average high temperature are January and December (25.7°F).
The month with the highest average low temperature is July (45.1°F).
The coldest month (with the lowest average low temperature) is February (17.1°F).
Average pressure
Juneau, AK
- Average pressure in January:
29.86"Hg - Average pressure in February:
29.96"Hg - Average pressure in March:
29.88"Hg - Average pressure in April:
29.92"Hg - Average pressure in May:
29.99"Hg - Average pressure in June:
29.96"Hg
- Average pressure in July:
30.03"Hg - Average pressure in August:
29.96"Hg - Average pressure in September:
29.89"Hg - Average pressure in October:
29.86"Hg - Average pressure in November:
29.8"Hg - Average pressure in December:
29.87"Hg
The month with the highest atmospheric pressure is July (30.03"Hg).
The month with the lowest atmospheric pressure is November (29.8"Hg).
Average wind speed
Juneau, AK
- Average wind speed in January:
6.9mph - Average wind speed in February:
6.3mph - Average wind speed in March:
6.2mph - Average wind speed in April:
4.7mph - Average wind speed in May:
4.1mph - Average wind speed in June:
3.7mph
- Average wind speed in July:
3.7mph - Average wind speed in August:
4.2mph - Average wind speed in September:
5.2mph - Average wind speed in October:
5.6mph - Average wind speed in November:
6.3mph - Average wind speed in December:
6.5mph
The windiest month (with the highest average wind speed) is January (6.9mph).
The calmest months (with the lowest average wind speed) are June and July (3.7mph).
Average humidity
Juneau, AK
The month with the highest relative humidity is January (92%).
The month with the lowest relative humidity is May (86%).
Average rainfall
Juneau, AK
- Average rainfall in January:
9.76" - Average rainfall in February:
6.69" - Average rainfall in March:
5.91" - Average rainfall in April:
6.02" - Average rainfall in May:
4.13" - Average rainfall in June:
4.53"
- Average rainfall in July:
4.61" - Average rainfall in August:
7.56" - Average rainfall in September:
8.27" - Average rainfall in October:
9.88" - Average rainfall in November:
9.53" - Average rainfall in December:
8.98"
The wettest month (with the highest rainfall) is October (9.88").
The driest month (with the least rainfall) is May (4.13").
Average rainfall days
Juneau, AK
- Average rainfall days in January:
9.3 days - Average rainfall days in February:
4.8 days - Average rainfall days in March:
5.3 days - Average rainfall days in April:
13.1 days - Average rainfall days in May:
18.5 days - Average rainfall days in June:
21.3 days
- Average rainfall days in July:
20.2 days - Average rainfall days in August:
21.6 days - Average rainfall days in September:
21.9 days - Average rainfall days in October:
20 days - Average rainfall days in November:
10.6 days - Average rainfall days in December:
5.8 days
The month with the highest number of rainy days is September (21.9 days).
The month with the least rainy days is February (4.8 days).
Average snowfall
Juneau, AK
- Average snowfall in January:
58.74" - Average snowfall in February:
48.5" - Average snowfall in March:
42.28" - Average snowfall in April:
29.45" - Average snowfall in May:
3.31" - Average snowfall in June:
0"
The month with the highest snowfall is December (62.8").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Juneau, AK
- Average snowfall days in January:
21.9 days - Average snowfall days in February:
18.3 days - Average snowfall days in March:
20.5 days - Average snowfall days in April:
15.9 days - Average snowfall days in May:
3.2 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
5.8 days - Average snowfall days in November:
19.2 days - Average snowfall days in December:
21.8 days
The month with the highest number of snowfall days is January (21.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature
Juneau, AK
The best month for swimming (with the highest average sea temperature) is August (53.5°F).
The coldest month (with the lowest average sea temperature) is March (40.3°F).
Average daylight / Average sunshine
Juneau, AK
- Average daylight in January:
7h and 18min - Average daylight in February:
9h and 24min - Average daylight in March:
11h and 54min - Average daylight in April:
14h and 30min - Average daylight in May:
16h and 48min - Average daylight in June:
18h and 12min
- Average daylight in July:
17h and 24min - Average daylight in August:
15h and 18min - Average daylight in September:
12h and 48min - Average daylight in October:
10h and 12min - Average daylight in November:
7h and 54min - Average daylight in December:
6h and 30min
The month with the longest days is June (Average daylight: 18h and 12min).
The month with the shortest days is December (Average daylight: 6h and 30min).
- Average sunshine in January:
2h and 48min - Average sunshine in February:
3h and 24min - Average sunshine in March:
4h and 36min - Average sunshine in April:
5h and 6min - Average sunshine in May:
6h and 12min - Average sunshine in June:
6h and 24min
- Average sunshine in July:
5h and 42min - Average sunshine in August:
5h and 6min - Average sunshine in September:
4h and 54min - Average sunshine in October:
3h and 6min - Average sunshine in November:
2h and 36min - Average sunshine in December:
2h and 54min
The month with the most sunshine is June (Average sunshine: 6h and 24min).
The month with the least sunshine is November (Average sunshine: 2h and 36min).
Average sunshine days
Juneau, AK
- Average sunshine days in January:
6.2 days - Average sunshine days in February:
8.7 days - Average sunshine days in March:
9.3 days - Average sunshine days in April:
7.5 days - Average sunshine days in May:
10 days - Average sunshine days in June:
6.3 days
- Average sunshine days in July:
8.8 days - Average sunshine days in August:
7.3 days - Average sunshine days in September:
7.5 days - Average sunshine days in October:
7 days - Average sunshine days in November:
6.1 days - Average sunshine days in December:
7.6 days
The month with the most sunshine days is May (10 days).
The month with the least sunshine days is November (6.1 days).
Average UV index
Juneau, AK
The months with the highest UV index are May and July (UV index 3).
The months with the lowest UV index are January, April, October, November and December (UV index 1).
Average cloud cover
Juneau, AK
The months with the most cloud cover are January and November (Cloud cover 72).
The month with the least cloud cover is May (Cloud cover 61).
Average visibility
Juneau, AK
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (4mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (4mi).
