August Weather in Juneau, United States

Last updated: February 24, 2025

In Juneau, United States, August offers a diverse weather experience, featuring a maximum temperature that can reach up to 27°C (80°F), while the average hovers around a mild 13°C (56°F). Visitors can expect cooler nights with minimum temperatures dropping to 4°C (40°F). The month is characterized by significant rainfall, with total precipitation amounting to 280 mm (11.0 in) over approximately 20 days, leading to a humidity level that often feels uncomfortably high at 108%. This blend of warm days and frequent showers makes August a unique time to explore the lush landscapes and vibrant wildlife of Juneau.

August Temperature in Juneau

In August, temperatures in Juneau, United States, begin to show the warmth of late summer, with a minimum of 4°C (40°F) and an average that holds steady at 13°C (56°F). The maximum can reach a pleasant 27°C (80°F), offering an inviting atmosphere for outdoor activities. This month marks a noticeable transition from the cooler temperatures of spring and early summer, where July's highs also peaked at 27°C (77°F). As the warm days of August draw to a close, the weather hints at the approaching fall, yet it retains the charm of mild conditions, making it a delightful time for visitors and locals alike to explore the natural beauty of this Alaskan gem.

August Weather in Juneau: Daily Temperature Highs, Lows, and Averages

The chart illustrates August temperature patterns in Juneau, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec252329364552565550393128
Data source: Temperature data for Juneau generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

August Precipitation in Juneau

August stands out as a notable month for precipitation in Juneau, with an impressive total of 280 mm (11.0 in) and 20 rainy days. This significant increase compared to July's 164 mm (6.5 in) reflects a shift in the weather pattern as summer transitions into fall. Following the lush summer months, this spike not only highlights August's role as one of the wetter periods in the year but also sets the stage for September's substantial 259 mm (10.2 in). Overall, the trend indicates that as we move deeper into the year, Juneau experiences progressively heavier rainfall, particularly evident in the autumn months, ultimately leading into the wetter than average winter season, where totals soar even higher.

August Precipitation Trends in Juneau

The chart displays monthly precipitation patterns in Juneau, with values for each month alongside August's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how August's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec215182175163174189164280259332267293
Data source: Precipitation data for August generated using information from the Copernicus Climate Change Service.
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August Humidity in Juneau

In Juneau, the journey through the humid months consistently showcases a dramatic rise in moisture levels. Starting with January's high of 94%, humidity levels remain relatively stable until June, where they spike to 96%. The trend continues upward through the summer, peaking in August at an impressive 108%, indicating the area's tendency to experience oppressive humidity. This peak is followed by a slight decrease in September, yet humidity remains notably high at 101%. Overall, Juneau's weather patterns highlight a distinct seasonal shift, with summer months bringing a noticeable surge in humidity that significantly influences the region's climate and comfort levels.

August Average Humidity in Juneau

This chart illustrates the average monthly humidity levels in Juneau, with August's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how August's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec94%90%92%92%90%96%104%108%101%98%97%96%
Data source: Humidity data for August generated using information from the Copernicus Climate Change Service.

August UV Index in Juneau

In August, Juneau experiences a UV Index of 9, categorizing exposure as very high and reducing the safe burn time to just 15 minutes. This pattern reflects a peak in solar radiation that begins in May and continues through July, indicating the summer months as the time to be particularly cautious about sun exposure. With the UV Index remaining elevated from June through August, it’s crucial for residents and visitors alike to employ sun protection strategies to safeguard their skin. As the season transitions into September, the index drops to 6, which, although still in the high category, offers a bit of relief as burn time increases to 25 minutes. For a more detailed look at the UV Index throughout the year, feel free to explore Juneau UV Index.

Maximum UV Index Levels in Juneau for August

The chart shows the monthly maximum UV Index (UVI) for Juneau in August, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec124588996311
Data source: Juneau August UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

August Sunshine in Juneau

In Juneau, the radiance of summer shines brightest as the months progress toward August, peaking in May with an impressive 235 hours of sunlight. While June still basks in 201 hours, the days begin to subtly shorten as August approaches, bringing 178 hours of warm sun. This trend of gradual decline continues into the fall, where September sees 167 hours, followed by a more pronounced drop as winter looms. The data tells a clear story of seasonal changes: the long summer days give way to a cool, crisp autumn, inviting visitors and locals alike to relish the lingering light before the dark winter months settle in.

Monthly Sunshine Duration in Juneau: August Highlighted

The August sunshine duration represents the total number of hours Juneau experiences direct sunlight during the month of August, excluding cloudy or obstructed periods. This chart compares the sunshine duration of August with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec43h125h179h218h235h201h198h178h167h103h58h45h
Data source: Juneau August Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Juneau During August

In Juneau, the likelihood of sunny weather in August is modest, with only a 17% chance of sunshine. This figure aligns closely with the fluctuations observed throughout the summer months, particularly July, which also boasts a 26% chance. Notably, the sunny opportunities in August decline as the year progresses from the sunnier spring months. While February showcases the highest chance at 36%, this trend toward drearier skies returns in early fall, with September dropping to just 8%. Thus, if you’re planning a sun-soaked getaway to Juneau in August, it’s wise to temper your expectations, as the cloud cover often reigns supreme in this beautiful Alaskan city.

Percentage of Sunny Days in August in Juneau

The chart illustrates the percentage of sunny days in Juneau throughout the year, with August highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Juneau experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec16%36%17%35%13%26%26%17%8%15%14%30%
Data source: Juneau August chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Juneau in August

In Juneau, the daylight duration showcases a dramatic seasonal shift, with August offering a delightful balance of 15 hours of sunlight. As the longest days are enjoyed in June, where daylight peaks at 18 hours, the gradual decrease begins in July and continues into August, hinting at the impending autumn. This transitional month marks a noticeable dip from the summer's vibrant light but still maintains a rich exposure compared to the winter months. Following this pattern, September drops to 12 hours of daylight, paving the way for the shorter days that return as the year moves toward December's mere 6 hours. This rhythm of daylight not only shapes daily life in Juneau but also highlights the city's incredible seasonal transformations.

Average Daylight Hours in Juneau for August

The chart illustrates the variation in daylight duration in Juneau throughout the year, with August highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec7h 13m9h 23m11h 54m14h 29m16h 50m18h 7m17h 23m15h 13m12h 42m10h 9m7h 47m6h 28m
Data source: Juneau daylight hours, calculated by summing the hours between sunrise and sunset for each day.

August Winds in Juneau

In August, Juneau experiences a subtle uptick in wind speed, averaging 1.9 m/s (4 mph), a slight increase from the summer’s calmest months. The data reflects a general trend of decreasing wind speeds from spring into mid-summer, with July hitting its lowest average of 1.4 m/s (3 mph). However, as August arrives, there’s a gentle shift towards slightly breezier afternoons, setting the stage for a transition into the more blustery autumn months. This rhythmic ebb and flow of wind highlights the unique climate of Juneau, where the calmness of summer eventually gives way to the invigorating winds of fall.

Average August Wind Speed in Juneau

The chart displays monthly wind speed patterns in Juneau, with values for each month shown alongside August's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how August's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.52.62.32.01.81.61.41.9 m/s2.22.52.42.5
Data source: Juneau August wind data, generated using information from the Copernicus Climate Change Service.

How August Weather in Juneau Compares to Other Months

The weather in Juneau changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of August's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Juneau and find detailed weather information for every month.

August and January in Juneau present a striking contrast in weather conditions. August experiences a milder climate, with temperatures ranging from a minimum of 4°C (40°F) to a maximum of 27°C (80°F), accompanied by significant precipitation totaling 280 mm (11.0 in) over 20 days. In contrast, January is marked by much colder temperatures, dipping as low as -25°C (-13°F) and peaking at a mere 8°C (47°F). Precipitation in January is lower at 215 mm (8.4 in) across 16 days, while humidity stands at a high 94%. For a detailed look at January weather specifics, check out Juneau weather in January.

August and February present striking contrasts in weather conditions. In August, the temperatures typically range from a chilly 4°C (40°F) at night to a warm 27°C (80°F) during the day, with an average of 13°C (56°F). This month is characterized by high precipitation, with approximately 280 mm (11.0 in) falling over about 20 days, creating a humid atmosphere with 108% humidity. In contrast, February features much colder temperatures, with nighttime lows reaching a frigid -24°C (-12°F) and daytime highs peaking at just 9°C (48°F), averaging -5°C (23°F). While February sees less precipitation at 182 mm (7.2 in) spread over 14 days, the humidity remains significant at 90%. For more details, you can explore Juneau weather in February.

August and March present strikingly different weather patterns. In August, temperatures range from a minimum of 4°C (40°F) to a maximum of 27°C (80°F), with an average of 13°C (56°F). This month experiences substantial rainfall, totaling 280 mm (11.0 in) over 20 days, contributing to a high humidity level of 108%. In contrast, March is much colder, with temperatures ranging from a frigid -18°C (0°F) to a maximum of 10°C (51°F) and an average of -1°C (30°F). Precipitation is lower, at 175 mm (6.9 in) over 17 days, and humidity sits at a still notable 92%. For a more detailed look at the weather in March, you can check Juneau weather in March.

In comparing the weather between April and August, it’s clear that August offers a much milder and wetter climate. While April experiences colder temperatures with a minimum of -13°C (9°F) and an average of only 2°C (36°F), August boasts a minimum of 4°C (40°F) and an average temperature of 13°C (56°F). Precipitation levels significantly differ as well, with August receiving 280 mm (11.0 in) over 20 days compared to April's 163 mm (6.4 in) across 17 days. Furthermore, the humidity in August reaches a notable 108%, while April maintains a lower humidity of 92%. To find out more about what to expect in April, you can check out this link: Juneau weather in April.

When comparing the weather in August and May, August offers warmer temperatures, with a minimum of 4°C (40°F) and an average of 13°C (56°F), peaking at 27°C (80°F). In contrast, May is cooler, with temperatures ranging from a minimum of -3°C (26°F) to a maximum of 21°C (70°F), averaging 7°C (45°F). Additionally, August experiences significantly higher precipitation, with 280 mm (11.0 in) over 20 days, compared to May's 174 mm (6.9 in) across 18 days. The humidity in August is particularly high at 108%, whereas May has a lower humidity level of 90%. For a detailed look at the weather in May, you can visit Juneau weather in May.

In comparing the weather of August and June, noticeable differences emerge. August typically experiences a broader temperature range with a minimum of 4°C (40°F) and a maximum of 27°C (80°F), resulting in an average temperature of 13°C (56°F). In contrast, June's temperatures are slightly cooler, with a minimum of 2°C (36°F) and a maximum of 25°C (77°F), averaging at 11°C (53°F). Additionally, August is marked by significantly higher precipitation, with 280 mm (11.0 in) spread over 20 days, while June sees 189 mm (7.4 in) over 22 days, indicating wetter conditions in August. The humidity is also noticeably higher in August, reaching 108% compared to June's 96%. For more detailed insights on June weather in Juneau, click here: Juneau weather in June.

August weather in Juneau shows a slight increase in maximum temperature compared to July, with highs reaching 27°C (80°F), while July tops out at 25°C (77°F). However, August is marked by significantly heavier rainfall, accumulating 280 mm (11.0 in) over 20 days, compared to July's 164 mm (6.5 in) over 18 days. Both months share the same average temperature of 13°C (56°F), but August's increased humidity at 108% suggests a more oppressive atmosphere. For more detailed insights, you can check out Juneau weather in July.

August typically sees warmer conditions than September, with temperatures ranging from a minimum of 4°C (40°F) to a maximum of 27°C (80°F) and an average of 13°C (56°F). In contrast, September experiences cooler averages, with temperatures dipping to a minimum of -4°C (26°F) and peaking at 23°C (74°F), resulting in an average of 10°C (50°F). Both months experience significant precipitation; however, August has slightly more at 280 mm (11.0 in) over 20 days compared to September’s 259 mm (10.2 in) over 17 days. Humidity levels also decline, with August recording a high of 108% and September at 101%. For more detailed insights, you can visit Juneau weather in September.

The weather in August and October presents a striking contrast in terms of temperature and precipitation. August typically has milder temperatures, ranging from a minimum of 4°C (40°F) to a maximum of 27°C (80°F), while October experiences much cooler conditions, with lows reaching -11°C (13°F) and highs peaking at 14°C (57°F). Rainfall is also more pronounced in October, with 332 mm (13.1 in) over 22 days, compared to August's 280 mm (11.0 in) over 20 days. The humidity remains high in both months, though slightly higher in August at 108% compared to October's 98%. For a more detailed overview of October weather, you can visit Juneau weather in October.

August and November present contrasting weather patterns, reflecting the transition from summer to winter. In August, temperatures range from a minimum of 4°C (40°F) to a maximum of 27°C (80°F), with an average of 13°C (56°F). The month sees significant precipitation, totaling 280 mm (11.0 in) over 20 days, contributing to a high humidity level of 108%. In stark contrast, November experiences much colder temperatures, with a minimum of -15°C (6°F), an average of -1°C (31°F), and a maximum of 8°C (47°F). Precipitation remains substantial at 267 mm (10.5 in) over 22 days, accompanied by humidity levels of 97%. This shift highlights the dramatic drop in temperatures and the persistence of wet conditions as summer gives way to winter. For more detailed weather insights, check out Juneau weather in November.

The weather in August and December presents a striking contrast in both temperature and precipitation patterns. In August, temperatures typically range from a mild 4°C (40°F) to a maximum of 27°C (80°F), accompanied by significant rainfall totaling 280 mm (11.0 in) over approximately 20 days, leading to a notably high humidity level of 108%. In contrast, December experiences much colder conditions, with temperatures plunging to a minimum of -24°C (-10°F) and averaging around -2°C (28°F), while the maximum temperature reaches only 10°C (50°F). Precipitation slightly increases to 292 mm (11.5 in) spread over 22 days, but the humidity remains lower at 96%. For more detailed insights on the December weather in Juneau, you can visit Juneau weather in December.

Compare Juneau's Climate with Cities Worldwide

Conclusion: What to Expect From August Weather in Juneau

August in Juneau brings a unique blend of summer warmth and the first hints of autumn, creating an atmosphere that's distinctly different from earlier months. While temperatures can reach pleasantly warm highs, they average cooler than July, making the air feel refreshingly crisp. As the humidity peaks and rain frequency increases, those planning outdoor activities should be prepared for a few wet days amidst the splashes of sunlight. This transitional month showcases the beauty of lush landscapes, vibrant colors, and perhaps even the last glimpse of summer adventures before the cooler months set in. For more details on what to expect throughout the year, check out Juneau Climate.