Last updated: February 24, 2025
December in Sun Valley, United States presents a charming yet chilly winter landscape, with temperatures ranging from a brisk -25°C (-12°F) at night to a maximum of 8°C (46°F) during the day. The average temperature hovers around a frosty -9°C (16°F), ideal for winter sports enthusiasts. Despite the cold, the month sees approximately 49 mm (1.9 in) of precipitation over 10 days, contributing to a humid atmosphere with levels reaching 87%. This combination of cold and moisture creates a picturesque setting, perfect for enjoying the snowy outdoors and cozying up by the fire.
In Sun Valley, United States, December temperatures mark a significant chill as winter fully sets in. With minimums plummeting to -25°C (-12°F) and an average hovering around -9°C (16°F), the landscape transforms into a frosty wonderland. The maximum temperature struggles to reach 8°C (46°F), hinting at the enduring chill throughout the month. This trend of dropping temperatures is a continuation from November, where the mercury had already dipped significantly, reinforcing the notion that December is among the coldest months of the year. Snow enthusiasts and winter lovers find joy in these conditions, as they signal ideal skiing and snowboarding opportunities in this picturesque mountain retreat. Overall, December in Sun Valley serves as a poignant reminder of winter's embrace, setting the stage for cozy festivities and exhilarating outdoor adventures.
In December, Sun Valley experiences a moderate shift in precipitation patterns, receiving approximately 49 mm (1.9 in) of rain over 10 days. This marks a slight decline compared to November's 46 mm but remains consistent with the late fall trend of steady precipitation. As winter approaches, the precipitation often transitions from rain to snow, enhancing the region's picturesque landscapes. While January typically sees 56 mm of rainfall over a similar number of days, December serves as a precursor to the heavier precipitation and snow that characterize the heart of winter in Sun Valley, setting the stage for seasonal festivities and winter sports.
As December graces Sun Valley with its presence, the humidity levels rise to an 87%, marking a notable increase as the year draws to a close. This spike follows a trend observed throughout the months, where humidity is highest in the early winter and remains relatively elevated as compared to the hotter summer months. In stark contrast, July boasts the lowest humidity at merely 53%, highlighting a summer dryness that gradually shifts toward dampness as fall settles in. The transition from the crisp air of November, with its 83% humidity, to December's more humid atmosphere signifies the approaching winter conditions. Overall, the data reveals a clear seasonal pattern where humidity peaks in the winter, reminding residents of the cozy chill enveloping Sun Valley.
As December settles into Sun Valley, the UV Index dips to 3, placing it in the moderate exposure category, which means residents and visitors can expect a burn time of about 30 minutes under direct sunlight. This trend marks a gentle decline from the higher UV levels experienced in the spring and summer months, with the Index reaching its peak of 12 in June. While the warmer months necessitate more vigilance against sunburn, December offers a reprieve, allowing for longer outdoor enjoyment with less risk to skin health. For more detailed information on the UV Index throughout the year, visit Sun Valley UV Index.
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In Sun Valley, December brings a gentle retreat from the sun-soaked summer days, with an average of 178 hours of sunshine—less than the brighter months but still a sparkling reminder of winter’s charm. As the year transitions, the sunlight gradually wanes from the peak of 402 hours in July to the softer glow of December, reflecting a broader trend of diminishing daylight during the colder months. Despite this decrease, December's hours of sunshine offer a warm embrace in the midst of winter, setting a picturesque scene as ski enthusiasts and nature lovers bask in the beauty of frosted slopes and serene landscapes. With winter's arrival, Sun Valley may not bask in the sun as long as it does during the summer, but the delightful December sunshine still invites exploration and enjoyment amidst the snow-covered peaks.
In Sun Valley, December signals a notable shift in weather patterns, bringing with it a lower likelihood of sunny days at just 27%. This decline is part of a broader trend observed as the year progresses; following a peak of 82% in September, the chances of sunshine steadily decrease into the winter months. As we transition from the vibrant summer, where sunlight is abundant, to the chillier depths of December, sunlight becomes increasingly scarce. With January and February still showing only a modest improvement at 35% and 40%, respectively, it's clear that those seeking warm, sunny days in the heart of winter may need to manage their expectations and embrace Sun Valley’s stunning winter landscape instead.
In Sun Valley, United States, daylight duration experiences a notable ebb and flow throughout the year, peaking in the lush days of summer. December stands out with just 8 hours of daylight, marking the culmination of a gradual decline that begins post-summer. As the end of the year approaches, the shorter days contrast sharply with the sun-drenched 15 hours enjoyed in June and July. Following the vibrant springs of 11 hours in March and the blooming 14 hours of May, daylight trickles down to its winter low. This seasonal rhythm highlights the transition from sunlit adventures in the warmer months to cozy, embracing nights as winter sets in, reminding us to cherish every fleeting ray of sunlight during the darker days of December.
As the year winds down in December, Sun Valley experiences a gentle breeze averaging 2.0 m/s (5 mph), mirroring the mild gusts of earlier months. The trend reveals a consistent airflow throughout the latter part of the year, with April through October showcasing an uptick in breezy days that average between 2.0 to 2.4 m/s (4 to 5 mph). While there is a slight dip in wind speed during the frigid January and November months, December maintains the charm of a soft winter wind. This steady current, characterized by a blend of tranquility and refreshing coolness, contributes to Sun Valley’s winter allure, making it a perfect backdrop for holiday adventures and festive gatherings.
The weather in Sun Valley 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 Sun Valley and find detailed weather information for every month.
In December, temperatures range from a chilly minimum of -25°C (-12°F) to a maximum of 8°C (46°F), with an average of -9°C (16°F). The month sees about 49 mm (1.9 in) of precipitation over 10 days, alongside a high humidity level of 87%. In contrast, January experiences even colder conditions, with minimum temperatures dropping to -27°C (-16°F), though the average slightly improves to -8°C (17°F). The maximum temperature in January is lower at 2°C (36°F), and precipitation increases to 56 mm (2.2 in), maintaining the same frequency of 10 rainy days but with higher humidity at 91%. For a more detailed look at the weather patterns, check out Sun Valley weather in January.
In December, temperatures typically range from a chilly minimum of -25°C (-12°F) to a maximum of 8°C (46°F), with an average temperature of -9°C (16°F). The month experiences about 49 mm (1.9 in) of precipitation over approximately 10 days, coupled with a humidity level of 87%. In contrast, February sees slightly milder temperatures, with a minimum of -22°C (-8°F) and a maximum of 6°C (42°F), yielding an average of -8°C (18°F). However, February tends to be wetter, featuring 86 mm (3.4 in) of precipitation over around 13 days, and a higher humidity of 92%. For more detailed insights, check out Sun Valley weather in February.
In December, temperatures can be quite frigid, with averages around -9°C (16°F) and lows dipping to -25°C (-12°F), while the weather remains relatively humid at 87%. The month sees around 49 mm (1.9 in) of precipitation spread over approximately 10 days. In contrast, March brings a slight warming trend, with average temperatures rising to -3°C (26°F) and a maximum of 10°C (50°F). However, it also tends to be wetter, with total precipitation reaching 60 mm (2.4 in) over about 12 days and humidity at a slightly lower 85%. For a detailed look at how weather conditions evolve during this transitional month, check out Sun Valley weather in March.
December and April present stark contrasts in weather patterns. December features much colder temperatures, with a minimum of -25°C (-12°F) and an average around -9°C (16°F), while April warms up significantly, offering milder conditions with an average temperature of 0°C (31°F) and a maximum of 14°C (57°F). Precipitation levels are similar, with December receiving 49 mm (1.9 in) over approximately 10 days, compared to April's 52 mm (2.0 in) across 11 days. Additionally, humidity levels in December are notably higher at 87%, compared to April's 76%. For those interested in more details, you can check out Sun Valley weather in April.
December and May present stark contrasts in weather patterns. In December, temperatures can plummet to as low as -25°C (-12°F), with an average hovering around -9°C (16°F), while the maximum can reach only 8°C (46°F). This chilling month experiences significant precipitation across about 10 days, with humidity levels peaking at 87%. In contrast, May brings a notable warmth, with minimum temperatures around -12°C (10°F) and average highs climbing to 24°C (75°F). Although May sees slightly more precipitation at 61 mm (2.4 in) across 13 days, the humidity is considerably lower at 66%. For a deeper look at the delightful weather conditions, check out Sun Valley weather in May.
In December, temperatures can plummet to a minimum of -25°C (-12°F), with an average around -9°C (16°F) and a maximum of 8°C (46°F). This month also sees higher humidity levels at 87%, coupled with about 49 mm (1.9 in) of precipitation spread over 10 days. In contrast, June offers a much milder climate, with temperatures ranging from a minimum of -4°C (24°F) to an average of 11°C (52°F) and peaking at 28°C (82°F). Precipitation in June is slightly lower at 46 mm (1.8 in), with rain occurring over just 9 days and a more comfortable humidity level of 62%. For a more detailed look at the weather in June, you can check Sun Valley weather in June.
When comparing the weather in December and July, the differences are striking. December experiences frigid temperatures, with a minimum of -25°C (-12°F) and an average of -9°C (16°F), often leading to a chilly atmosphere with high humidity at 87%. The month sees precipitation on about 10 days, accumulating to 49 mm (1.9 in). In contrast, July brings much warmer conditions, characterized by a minimum of 0°C (32°F) and an average of 16°C (62°F), reaching a pleasant maximum of 28°C (83°F). With significantly lower humidity at 53% and only about 4 days of precipitation totaling 15 mm (0.6 in), July presents a much drier and sunnier disposition. For more details on what to expect during this summer month, check out Sun Valley weather in July.
December and August present stark contrasts in weather. In December, temperatures can plunge as low as -25°C (-12°F), with an average of -9°C (16°F) and a maximum of only 8°C (46°F). This month also sees significant cloud cover, with around 49 mm (1.9 in) of precipitation over approximately 10 days and a high humidity level of 87%. In contrast, August offers a much milder climate, with temperatures ranging from a minimum of -3°C (27°F) to a maximum of 30°C (86°F) and an average temperature of 15°C (60°F). August experiences less precipitation, totaling 33 mm (1.3 in) over just 6 days, and a humidity level that drops to 42%. For more details on August weather, check out Sun Valley weather in August.
December and September exhibit stark contrasts in weather conditions. In December, temperatures plummet, with a minimum of -25°C (-12°F) and an average of -9°C (16°F), leading to a cold and often harsh winter experience. Precipitation is more frequent, occurring on about 10 days, and the humidity is notably high at 87%, contributing to a damp chill in the air. In contrast, September boasts milder temperatures, with a minimum of -13°C (10°F) and a pleasant average of 10°C (51°F), peaking at a warm 29°C (84°F). Precipitation is less frequent, averaging only 30 mm (1.2 in) over approximately 5 days, coupled with a lower humidity level of 46%, making it a far more comfortable month. For detailed insights into September's weather, you can check out Sun Valley weather in September.
When comparing the weather in December to that of October, notable differences emerge. December experiences much colder temperatures, with an average of -9°C (16°F) compared to October's milder average of 2°C (35°F). Additionally, while December sees maximum temperatures peak at 8°C (46°F), October boasts highs reaching up to 22°C (71°F), making it significantly warmer overall. Precipitation is slightly higher in December at 49 mm (1.9 in) over 10 days, compared to October's 42 mm (1.6 in) spread over 7 days. Furthermore, December's humidity is markedly higher at 87%, contrasting with October’s more comfortable 64%. For more details on October's weather, you can check Sun Valley weather in October.
In December, the weather takes a colder turn compared to November, with average temperatures dropping to -9°C (16°F) from November's -4°C (26°F). While both months experience cold minimum temperatures, December tends to be chillier, reaching lows of -25°C (-12°F) compared to November's -23°C (-10°F). Additionally, December sees slightly more precipitation, with 49 mm (1.9 in) over 10 days, while November has 46 mm (1.8 in) over 9 days. Humidity levels increase slightly in December, averaging 87% compared to November's 83%. For more details about the climate during this time, you can check out Sun Valley weather in November.
December in Sun Valley ushers in a striking shift from the milder seasons, with temperatures plunging to their annual lows and the air feeling significantly crisper. The combination of frequent precipitation over about ten days creates a winter wonderland, making the landscape stunningly picturesque. With high humidity levels reaching 87%, the cold can feel even more intense, wrapping the area in a chilly embrace. As the month progresses, this substantial drop in temperatures and increase in moisture not only sets the stage for winter activities but also contrasts sharply with the milder autumn months prior. For a more in-depth look at how Sun Valley's December weather fits into the larger climate picture, check out Sun Valley Climate.