Climate in Juneau (Alaska)

In southeastern Alaska, at 58 degrees north latitude and west of the Canadian province of British Columbia, lies the state capital of Alaska, Juneau, where there is a moderately continental climate, with cold winters, during which the average temperature is slightly below freezing (the January average is -2 °C or 28.5 °F), and mild summers (highs in July are of 18 °C or 64 °F).
The city is located on the coast, but in an area of islands and fjords, and 120 km (75 mi) from the coast of the Pacific Ocean. To thw west, across the Gastineau Channel, on Douglas Island are the towns of Douglas and West Juneau.
In the east, on the other hand, in the immediate vicinity is the mountain range that marks the border with Canada (Alaska Boundary Range). The mountains are perennially covered in snow already above 1,100 metres (3,600 feet), furthermore, some glaciers enter directly into the sea.

The average temperature ranges from about -2 °C in January to about 14 °C in July.

Precipitation is abundant (although less than on the coast directly exposed to the Pacific Ocean), in fact, it is about 1,700 mm (67 inches) per year, with a peak from August to December. Snowfalls are abundant and occur from late October to early April, totaling 2.2 meters (88 inches) per year.



In winter, the ground is often covered with snow, however, there are quite mild periods, in which the temperature is just above freezing, and rain falls, or rain mixed with snow.
However, there are also cold periods, more or less long depending on the winter, in which the temperature drops below freezing and stays below even during the day. These periods are usually dry, as currents from the east prevail, however, it can sometimes snow.
On the coldest days of the year, the temperature generally drops to around -18 °C (-0.5 °F), although it can drop to lower values from time to time. The coldest record is -30 °C (-22 °F) and was set in February 1968 and January 1972.

The summer is mild, with frequent rains, which gradually increase.
On the hottest days of the year, the temperature generally reaches 27/28 °C (81/82 °F). In July 1975 it reached 32.2 °C (90 °F), while in July 2016 it reached 31.5 °C (88.7 °F).

In Juneau, the amount of sunshine is not great, since the rains are frequent; nevertheless, the sunniest season, albeit slightly, is spring. April and May are the sunniest months, while October, November and December are the cloudiest ones.

Near Juneau and along the southeast coast, the sea temperature is similar to that of Anchorage and the south coast.

Best Time

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The best time to visit Juneau is summer, from June to August, being the mildest season. It must be said that the rains are frequent, especially in August, when they are also more abundant.
In May it can get cold, especially in the first half of the month, but the days are already long, the sun shines more often and the rains are a bit less frequent than in summer.

Juneau - Climate data

In Juneau, the average temperature of the coldest month (January) is of -2 °C (28.4 °F), that of the warmest month (July) is of 14 °C (57.1 °F). Here are the average temperatures.
Precipitation amounts to 1700 millimeters (66.9 inches) per year: it is therefore abundant. It ranges from 88.1 mm (3.5 in) in the driest month (April) to 232.4 mm (9.1 in) in the wettest one (September). Here is the average precipitation.
The sea temperature ranges from 4 °C (39 °F) in February, March to
There are on average around 1530 sunshine hours per year. Here are the average hours of sunshine per day.

Juneau - Weather by month

Based on the period 1991-2020

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January, the coldest month of the year, is generally a very cold month. The average temperature is of -2 °C (28 °F), with a minimum of -4.6 °C (23.7 °F) and a maximum of 0.6 °C (33.1 °F).
On the coldest nights of the month, the temperature usually drops to around -14.5 °C (6 °F).
On the warmest days of the month, the temperature usually reaches around 7.5 °C (45 °F).
Precipitation amounts to 152.9 mm (6 in), distributed over 17 days.
The day lasts on average 9 hours and 25 minutes.
There are on average 2.5 hours of sunshine per day. So, the sun shines 28% of the time.
The average humidity is 80%. Hence, the air is normally humid.
The average wind speed is 17 kph (11 mph).
The average sea temperature is of 4.5 °C (39.5 °F). Therefore, the sea is very cold for swimming.

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February is generally a very cold month. The average temperature is of -1 °C (30 °F), with a minimum of -4.1 °C (24.6 °F) and a maximum of 2 °C (35.6 °F).
On the coldest nights of the month, the temperature usually drops to around -12.5 °C (9.5 °F).
On the warmest days of the month, the temperature usually reaches around 7.5 °C (45.5 °F).
Precipitation amounts to 109.4 mm (4.3 in), distributed over 14 days.
The day lasts on average 10 hours and 35 minutes.
There are on average 3 hours of sunshine per day. So, the sun shines 30% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is 16 kph (10 mph).
The average sea temperature is of 4 °C (39 °F). Therefore, the sea is very cold for swimming.

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March is generally a cold month. The average temperature is of 0.5 °C (33 °F), with a minimum of -3 °C (26.6 °F) and a maximum of 4 °C (39.2 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -11 °C (12 °F).
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 9.5 °C (49.5 °F).
Precipitation amounts to 93.2 mm (3.7 in), distributed over 14 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 37% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is 14 kph (9 mph).
The average sea temperature is of 4 °C (39 °F). Therefore, the sea is very cold for swimming.

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April is generally a quite cold month. The average temperature is of 4.9 °C (41 °F), with a minimum of 0.5 °C (32.9 °F) and a maximum of 9.3 °C (48.7 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -5 °C (23 °F).
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 16.5 °C (61.5 °F).
Precipitation amounts to 88.1 mm (3.5 in), distributed over 14 days.
The day lasts on average 13 hours and 30 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 45% of the time.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is 10 kph (6 mph).
The average sea temperature is of 5 °C (40.5 °F). Therefore, the sea is very cold for swimming.

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May is generally a mild month. The average temperature is of 9.4 °C (49 °F), with a minimum of 4.6 °C (40.3 °F) and a maximum of 14.2 °C (57.6 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -0.5 °C (31.5 °F).
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 22.5 °C (72 °F).
Precipitation amounts to 89.1 mm (3.5 in), distributed over 13 days.
The day lasts on average 14 hours and 40 minutes. So the days are long.
There are on average 7.5 hours of sunshine per day. So, the sun shines 51% of the time.
The average humidity is 76%. Hence, the air is normally humid.
The average wind speed is 8 kph (5 mph).
The average sea temperature is of 7.5 °C (46 °F). Therefore, the sea is very cold for swimming.

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June is generally a mild month. The average temperature is of 12.5 °C (55 °F), with a minimum of 8.2 °C (46.8 °F) and a maximum of 16.9 °C (62.4 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 3.5 °C (38.5 °F).
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 25.5 °C (78 °F).
Precipitation amounts to 97 mm (3.8 in), distributed over 13 days.
The day lasts on average 15 hours and 25 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 6.5 hours of sunshine per day. So, the sun shines 41% of the time.
The average humidity is 78%. Hence, the air is normally humid.
The average wind speed is 8 kph (5 mph).
The average sea temperature is of 11 °C (52 °F). Therefore, the sea is very cold for swimming.

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July, the warmest month of the year, is generally a mild month. The average temperature is of 14 °C (57 °F), with a minimum of 10.1 °C (50.2 °F) and a maximum of 17.8 °C (64 °F).
On the coldest nights of the month, the temperature usually drops to around 6.5 °C (43.5 °F).
On the warmest days of the month, the temperature usually reaches around 25.5 °C (77.5 °F).
Precipitation amounts to 130.5 mm (5.1 in), distributed over 15 days.
The day lasts on average 15 hours and 0 minutes. So the days are long.
There are on average 6 hours of sunshine per day. So, the sun shines 39% of the time.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is 8 kph (5 mph).
The average sea temperature is of 13 °C (55.5 °F). Therefore, the sea is very cold for swimming.

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August is generally a mild month. The average temperature is of 13.4 °C (56 °F), with a minimum of 9.5 °C (49.1 °F) and a maximum of 17.2 °C (63 °F).
On the coldest nights of the month, the temperature usually drops to around 5 °C (41.5 °F).
On the warmest days of the month, the temperature usually reaches around 24.5 °C (76.5 °F).
Precipitation amounts to 162.9 mm (6.4 in), distributed over 16 days.
The day lasts on average 13 hours and 55 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 37% of the time.
The average humidity is 84%. Hence, the air is normally humid.
The average wind speed is 8 kph (5 mph).
The average sea temperature is of 13 °C (55.5 °F). Therefore, the sea is very cold for swimming.

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September is generally a mild month. The average temperature is of 10 °C (50 °F), with a minimum of 6.7 °C (44.1 °F) and a maximum of 13.4 °C (56.1 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 0.5 °C (32.5 °F).
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 19 °C (66.5 °F).
Precipitation amounts to 232.4 mm (9.1 in), distributed over 20 days.
The day lasts on average 12 hours and 25 minutes.
There are on average 3.5 hours of sunshine per day. So, the sun shines 29% of the time.
The average humidity is 88%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 10.5 °C (51 °F). Therefore, the sea is very cold for swimming.

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October is generally a quite cold month. The average temperature is of 5.7 °C (42 °F), with a minimum of 2.9 °C (37.2 °F) and a maximum of 8.5 °C (47.3 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -4 °C (25 °F).
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 13 °C (56 °F).
Precipitation amounts to 213.9 mm (8.4 in), distributed over 20 days.
The day lasts on average 11 hours and 0 minutes.
There are on average 2 hours of sunshine per day. So, the sun shines 19% of the time.
The average humidity is 88%. Hence, the air is normally humid.
The average wind speed is 13 kph (8 mph).
The average sea temperature is of 8 °C (46 °F). Therefore, the sea is very cold for swimming.

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November is generally a cold month. The average temperature is of 1 °C (34 °F), with a minimum of -1.5 °C (29.3 °F) and a maximum of 3.5 °C (38.3 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around -9.5 °C (14.5 °F).
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 8.5 °C (47.5 °F).
Precipitation amounts to 166.2 mm (6.5 in), distributed over 18 days.
The day lasts on average 9 hours and 40 minutes.
There are on average 2 hours of sunshine per day. So, the sun shines 20% of the time.
The average humidity is 85%. Hence, the air is normally humid.
The average wind speed is 16 kph (10 mph).
The average sea temperature is of 6 °C (42.5 °F). Therefore, the sea is very cold for swimming.

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December is generally a very cold month. The average temperature is of -1 °C (30 °F), with a minimum of -3.4 °C (25.9 °F) and a maximum of 1.5 °C (34.7 °F).
On the coldest nights of the month, the temperature usually drops to around -13 °C (9 °F).
On the warmest days of the month, the temperature usually reaches around 7.5 °C (45 °F).
Precipitation amounts to 165.9 mm (6.5 in), distributed over 17 days.
The day lasts on average 9 hours and 0 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 1.5 hours of sunshine per day. So, the sun shines 15% of the time.
The average humidity is 83%. Hence, the air is normally humid.
The average wind speed is 17 kph (11 mph).
The average sea temperature is of 5 °C (41.5 °F). Therefore, the sea is very cold for swimming.