Last updated: February 24, 2025
Seattle's December weather presents a dynamic blend of chilly temperatures and frequent rainfall. With a maximum temperature reaching 14°C (58°F) and an average of 6°C (42°F), the city experiences a notable drop, with minimums dipping to -7°C (20°F). Rainfall is substantial, totaling 196 mm (7.7 in) over 19 days, contributing to a humid atmosphere with an average humidity level of 88%. This month captures the essence of Seattle's winter, characterized by a cool, wet ambiance that invites both locals and visitors to embrace the city's cozy charm.
In December, Seattle experiences its winter chill, with temperatures dipping to a minimum of -7°C (20°F) and peaking at a mild 14°C (58°F). The average sits around 6°C (42°F), reflecting a notable drop from the warmer months. As the year draws to a close, the city trades its vibrant summer warmth for brisk, crisp air, signaling a transition toward the colder depths of winter. This month’s temperatures highlight a trend of coolness and freshness, inviting residents and visitors alike to embrace the season’s charm while enjoying cozy indoor activities as well as the festive spirit in the city.
December in Seattle marks a peak in precipitation, reflecting the city's signature winter weather. With 196 mm (7.7 in) of rain falling over 19 days, this month stands out as the rainiest of the year, following closely behind November's impressive totals. As temperatures drop and days grow shorter, the transition from autumn to winter becomes starkly apparent, with December's precipitation nearly 8% higher than in November. This trend underscores Seattle's reputation for a moist maritime climate, where the arrival of winter brings an additional layer of atmospheric humidity, making the region's landscapes lush and vibrant. The continuous drizzle often invites locals and visitors alike to embrace cozy indoor activities, reinforcing the city's charm even amidst the rainfall.
December brings high humidity levels to Seattle, averaging around 88%, which is notably higher than the preceding month of November. This trend reflects the city’s characteristic winter weather, where moisture-laden air typically settles in as temperatures drop. Interestingly, while humidity peaks in December, it shows a gradual decrease from summer's lower levels, with August recording a dry 63%. As the year progresses, Seattleites experience a shift from the crisp, drier months of summer to the heavier, more humid atmosphere of winter, emphasizing the city's unique coastal climate and its influence on daily life.
In December, Seattle experiences a notably low UV Index of 1, categorizing exposure as minimal and allowing for a burn time of 45 minutes. This decline in UV radiation follows a gradual increase from the previous months, peaking in the summer with very high levels in June and July. Overall, Seattle’s UV Index trends reveal that winter months consistently feature lower exposure levels, making December a time when outdoor enthusiasts can enjoy the crisp weather without significant concerns about sunburn. To learn more about UV trends throughout the year, visit Seattle UV Index.
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In Seattle, December offers a gentle farewell to the year with 93 hours of sunshine, a modest decline that follows the gradual descent from the peak summer months. As the year transitions from vibrant summer days—where sunlight reaches a luxurious 361 hours in July—toward the gray, overcast days of late autumn, December's sunlight represents a shift into the colder months. This trend underscores a significant seasonal pattern, with sunlight peaking in the summer and dipping as the year wanes. Though December may lack the golden rays of summer, it serves as a reminder of the sun's warmth before the longer nights of winter fully envelop the city.
As winter settles in, Seattle's likelihood of sunny weather in December drops to a modest 12%, reflecting the city’s characteristic gray skies. This trend marks a significant decline from the sunnier months of summer, where July enjoys a robust 63% chance of sunshine. The gradual decrease in daylight hours and increasing rainfall come to a head in December, making it the month with the second-lowest probability of sun, just above November. With the sharp contrast in sunshine percentages, it's clear that if you're dreaming of a bright December day in Seattle, you'll need to keep those expectations in check!
As the year unfolds in Seattle, the rhythmic dance of daylight reveals a captivating seasonal pattern. December, with its 8 hours of daylight, mirrors the fleeting light of January, marking the depths of winter when the sun lingers just above the horizon. This brief illumination contrasts sharply with the vibrant 15 hours seen in May and June, the peak of summer, where daylight reigns supreme. As spring approaches in March, there’s a gradual increase, leading to longer days that awaken life in the city. However, come November, daylight wanes again, setting the stage for a return to the shorter days of winter. This cyclical journey from the least to the most daylight not only marks the passage of seasons but also influences the mood and activities of Seattle’s inhabitants, making each month a unique experience in the city's atmospheric charm.
As December arrives in Seattle, the winds pick up slightly, averaging 3.4 m/s (8 mph), making it one of the breezier months of the year. This marks a continuation of the upward trend in wind speed observed during the fall, particularly from November to December. While January through March witness a dip in gusty conditions, with speeds fluctuating around 2.4 to 2.8 m/s (5 to 6 mph), the later months bring a refreshing increase. Notably, the summer months see the calmest breezes, with July dropping to a gentle 1.9 m/s (4 mph), but as the year wraps up, Seattle's winds remind us of winter's presence, invigorating the city with energy as it heads toward the new year.
The weather in Seattle changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of December's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Seattle and find detailed weather information for every month.
In December, the weather typically features a minimum temperature of -7°C (20°F), with an average of 6°C (42°F) and a maximum reaching up to 14°C (58°F). This month sees significant precipitation, with 196 mm (7.7 in) spread over 19 days and high humidity levels at 88%. In contrast, January maintains similar temperature ranges, with the minimum remaining at -7°C (19°F), an average of 6°C (43°F), and a maximum of 14°C (57°F). However, January experiences slightly less precipitation at 175 mm (6.9 in) over 16 days, along with slightly lower humidity at 86%. Overall, both months exhibit comparable temperatures, but January tends to be a bit drier. For a more detailed look at the weather in January, you can visit Seattle weather in January.
December and February share some similarities in weather patterns, yet there are distinct differences. Both months experience a maximum temperature of 14°C (58°F), but December has a slightly higher average temperature of 6°C (42°F) compared to February's average of 5°C (41°F). Precipitation levels in December are slightly higher at 196 mm (7.7 in), while February sees a total of 177 mm (7.0 in), both occurring over 19 days. Humidity remains relatively high in both months, with December averaging 88% and February at 86%. For more detailed information on February weather, you can visit Seattle weather in February.
December in Seattle is characterized by colder temperatures, with minimums dropping to -7°C (20°F) and an average of 6°C (42°F). The month experiences significant precipitation, averaging 196 mm (7.7 in), over 19 days, contributing to a high humidity level of 88%. In contrast, March brings a slight warming trend, with minimum temperatures around -1°C (31°F) and average highs reaching 7°C (46°F) and max temperatures climbing to 22°C (72°F). Precipitation during this month is lower, at 126 mm (4.9 in), occurring over 17 days while maintaining a similar humidity level of 87%. For more detailed weather information, visit Seattle weather in March.
December and April showcase a significant contrast in weather, reflecting the transition from winter to spring. In December, temperatures range from a frigid minimum of -7°C (20°F) to a milder maximum of 14°C (58°F), with an average temperature around 6°C (42°F). The month is characterized by high precipitation, totaling 196 mm (7.7 in) over 19 days, coupled with high humidity at 88%. Conversely, April brings a noticeable warming trend, with minimum temperatures rising to 1°C (34°F) and maximums reaching 24°C (75°F), alongside an average of 10°C (50°F). April also sees reduced precipitation, measuring 117 mm (4.6 in) over 14 days, and slightly lower humidity at 84%. For more specifics on the weather in April, you can check out Seattle weather in April.
December weather is characterized by colder temperatures, with minimums plummeting to -7°C (20°F) and an average temperature around 6°C (42°F). The month experiences significant precipitation, totaling 196 mm (7.7 in) over approximately 19 days, and a high humidity level of 88%, contributing to a damp and chilly atmosphere.
In contrast, May brings much milder conditions, with minimum temperatures starting at 5°C (42°F) and average highs reaching 14°C (57°F). Precipitation decreases significantly to 68 mm (2.7 in) over about 12 days, and humidity is slightly lower at 81%. This results in a more pleasant, spring-like experience, making it a favorable time for outdoor activities. For more details, you can check Seattle weather in May.
December and June present starkly contrasting weather patterns. In December, temperatures can dip as low as -7°C (20°F), with an average of 6°C (42°F) and a peak at 14°C (58°F). This month also experiences a significant amount of precipitation, totaling 196 mm (7.7 inches) over 19 days, coupled with high humidity levels at 88%. In contrast, June offers a much warmer climate, with temperatures ranging from a minimum of 8°C (46°F) to a maximum of 38°C (101°F), and an average temperature of 17°C (62°F). Precipitation in June is considerably lower at 63 mm (2.5 inches) over just 9 days, along with a slight decrease in humidity to 82%. For more details on Seattle's June weather, visit Seattle weather in June.
December weather presents a stark contrast to July's milder conditions. With average temperatures ranging from a chilly -7°C (20°F) to a maximum of 14°C (58°F), December experiences a notable cold snap, while July enjoys a warmer climate with temperatures hovering between 11°C (52°F) and a high of 32°C (91°F). Additionally, December sees significantly more precipitation, averaging 196 mm (7.7 in) over 19 days, compared to the much drier July, which typically receives only 18 mm (0.7 in) across just 5 days. Humidity levels are also higher in December at 88%, whereas July's humidity is milder at 79%. For more detailed insights into July weather, visit Seattle weather in July.
December weather is characterized by significantly colder temperatures, with average highs around 6°C (42°F) and lows plummeting to -7°C (20°F). In contrast, August boasts much warmer conditions, with average temperatures reaching a max of 33°C (93°F) and a comfortable minimum of 10°C (51°F). Additionally, December experiences higher precipitation, averaging 196 mm (7.7 in) over 19 days, while August is relatively dry with only 16 mm (0.6 in) of rain across just 5 days. The humidity levels also contrast sharply, sitting at 88% in December compared to a more moderate 63% in August. For more details, check out Seattle weather in August.
December and September present stark contrasts in weather conditions. In December, temperatures can drop as low as -7°C (20°F), with an average of 6°C (42°F) and a maximum of 14°C (58°F), creating a chilly atmosphere. This month also experiences significant precipitation, totaling 196 mm (7.7 in) over 19 days, and high humidity levels at 88%.
In contrast, September boasts much milder temperatures, ranging from a minimum of 8°C (46°F) to a maximum of 30°C (86°F), with an average temperature of 16°C (62°F). Precipitation is less frequent, with about 100 mm (3.9 in) over just 12 days, and humidity levels are considerably lower at 62%. For more details about the pleasant Seattle weather in September, visit Seattle weather in September.
In comparing the weather of December and October, we see a notable shift in temperature and precipitation patterns. December experiences colder temperatures, with minimums reaching -7°C (20°F) and average highs around 6°C (42°F), while October is milder, with minimums of -1°C (30°F) and maximums peaking at 23°C (74°F). Precipitation is more frequent in December, totaling 196 mm (7.7 in) across 19 days, compared to October's 155 mm (6.1 in) over 15 days. Additionally, December's humidity is slightly higher at 88%, compared to October's 83%. For more details on October's weather, you can check out Seattle weather in October.
December weather is generally colder and wetter than November, with average temperatures ranging from a minimum of -7°C (20°F) to a maximum of 14°C (58°F), compared to November's milder range of -1°C (30°F) to 17°C (63°F). While both months experience significant precipitation, December sees slightly more, with 196 mm (7.7 in) over 19 days, compared to November's 181 mm (7.1 in) across 18 days. Humidity levels remain fairly comparable, with December at 88% and November at 89%. For more detailed information, you can explore Seattle weather in November.
As December settles in over Seattle, the city experiences a significant shift in weather, marked by chilly temperatures that contrast sharply with the milder months. With an average temperature of around 6°C (42°F) and frequent dips below freezing, residents feel the bite of winter, especially at night. This month also brings a notable increase in precipitation, with nearly two-thirds of December days receiving some form of rain, leading to a total accumulation of 196 mm (7.7 in). The high humidity levels add an extra layer of dampness to the air, making this month distinctly different from the drier and warmer conditions earlier in the year. For a deeper understanding of how Seattle's weather unfolds throughout the year, visit Seattle Climate.