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December Weather in Unalaska, United States

Last updated: June 24, 2025

In December, the average temperature in Unalaska, United States hovers around 0°C (32°F), with a minimum chilling down to -11°C (13°F) and a maximum reaching 8°C (47°F). Expect about 157 mm (6.2 in) of precipitation over 20 days, contributing to an average humidity of 82%. Prepare for a cool and damp month!

December Temperature in Unalaska

In December in Unalaska, the average temperature is 0°C (32°F). Maximums can reach 8°C (47°F), and minimums can drop as low as -11°C (13°F). Be prepared for cold weather and dress in layers if you plan to travel during this time.

December Weather in Unalaska: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Unalaska, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Unalaska, December typically has an average temperature of 0°C (32°F), with highs reaching up to 8°C (47°F) and lows dropping to around -11°C (13°F).
JanFebMarAprMayJunJulAugSepOctNovDec303332354045505147423632
Data source: Temperature data for Unalaska generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Unalaska

In Unalaska in December, the precipitation amount is 157 mm (6.2 in) spread over 20 days.

December Precipitation Trends in Unalaska

The chart displays monthly precipitation patterns in Unalaska, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Unalaska, December typically receives around 157 mm (6.2 inches) of precipitation spread over approximately 20 days.
JanFebMarAprMayJunJulAugSepOctNovDec9515792991151006589117147113157
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Unalaska

In Unalaska in December, humidity is 82%. With an average temperature of 0°C (32°F), this humidity feels like an icy breath enveloping you, making each step outdoors a challenge as the cold dampness seeps into your clothes, chilling you to the bone and sapping your energy while traveling.

December Average Humidity in Unalaska

This chart illustrates the average monthly humidity levels in Unalaska, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Unalaska is approximately 82%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec83%84%83%84%90%93%95%92%86%82%81%83%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Unalaska

In Unalaska in December, the maximum UV index is 1, which corresponds to a low Exposure Category. This means you have a time to burn of 45 minutes. For more details, you can check the Hourly UV Index in Unalaska.

Maximum UV Index Levels in Unalaska for December

The chart shows the monthly maximum UV Index (UVI) for Unalaska in December, 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. In December, the maximum UV index in Unalaska typically reaches 1, which falls under the low exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec123567885321
Data source: Unalaska December 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.

How December Weather in Unalaska Compares to Other Months

Weather in Unalaska varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Unalaska, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Unalaska, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-1°C (30°F)95 mm (3.8 inches)83%low
February Weather1°C (33°F)157 mm (6.2 inches)84%low
March Weather0°C (32°F)92 mm (3.6 inches)83%moderate
April Weather2°C (35°F)99 mm (3.9 inches)84%moderate
May Weather4°C (40°F)115 mm (4.5 inches)90%high
June Weather7°C (46°F)100 mm (3.9 inches)93%high
July Weather10°C (50°F)65 mm (2.6 inches)95%very high
August Weather11°C (51°F)89 mm (3.5 inches)92%very high
September Weather9°C (48°F)117 mm (4.6 inches)86%moderate
October Weather5°C (42°F)147 mm (5.8 inches)82%moderate
November Weather2°C (37°F)113 mm (4.5 inches)81%low
December Weather0°C (32°F)157 mm (6.2 inches)82%low

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