Last updated: February 24, 2025
In December, Keystone, United States experiences a chilly climate characterized by an average temperature of -11°C (13°F), with daily maximums reaching a brisk 8°C (47°F) and plunging to minimums of -29°C (-20°F). The region records approximately 43 mm (1.7 in) of precipitation over 10 days, contributing to the winter landscape. With humidity levels peaking at 89%, the air can feel particularly frigid, making it essential for visitors and residents alike to bundle up and embrace the seasonal charm of Keystone’s winter wonderland.
In Keystone, United States, December marks the arrival of winter's chill, with temperatures consistently low. The month brings a stark minimum temperature of -29°C (-20°F), a trend consistent with the preceding months as the region experiences a deep freeze. The average temperature hovers around a biting -11°C (13°F), reflecting the season's grasp. Despite the frigid conditions, the maximum temperature can reach a mild 8°C (47°F), offering a brief reprieve from the cold. December's frigid temperatures fit within a broader pattern of progressively declining temperatures from the more temperate conditions of autumn, culminating in one of the coldest months of the year. As the winter solstice approaches, residents of Keystone brace for brisk days and tranquil, snowy nights.
December in Keystone sees a precipitation total of 43 mm (1.7 in), a slight dip from the preceding months but consistent with the winter season's typical moisture levels. With 10 precipitation days, the month features a balance of damp spells and intervals of clearer skies, making it a transitional period as the region shifts deeper into winter. Compared to the wetter months of April and May, which boast averages above 78 mm, December's precipitation reflects a general decline typical in late fall, while still ensuring the landscape remains hydrated. This trend, alongside relatively stable temperatures, sets the stage for a serene winter atmosphere, often enhanced by a dusting of snow that captures the charm of the holiday season.
In Keystone, United States, December marks a notable shift in humidity levels, wrapping up the year with a brisk 89% humidity. This increase signals a return to higher moisture levels after a gradual decline through the summer months, where July recorded the lowest humidity at just 52%. As the seasons transition, the humidity begins to rise in tandem with cooler temperatures, peaking again in late fall with November's 82%. Interestingly, the trend shows a consistent pattern of decreased humidity from early spring (March's 81%) to the end of summer, only to rebound sharply as winter approaches. December's elevated humidity not only adds a chill to the air but also hints at the seasonal moisture that blankets Keystone during its coldest months.
In December, the UV Index in Keystone, United States, decreases to a moderate level of 4, which allows for a more forgiving outdoor experience with a burn time of about 30 minutes. This marks a continuation of the trend from the previous months, where the UV Index saw a gradual decline from the extreme levels experienced in the summer. Starting at 13 in July and tapering off to 5 in November, UV exposure risks diminish, making outdoor activities safer. As winter approaches, it’s essential to stay mindful of UV exposure, even on cooler days; for more information, visit Keystone UV Index.
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In Keystone, United States, December marks the transition into winter, yet it still offers a generous 237 hours of sunshine. As the year winds down, this month experiences less sunlight compared to the vibrant peak of summer, where June and July bask in 382 hours of sunlight each. Interestingly, while December's light diminishes from the exuberance of late spring and summer, it still outshines the early winter months like January, which sees only 183 hours. This seasonal trend highlights a gradual decline in daylight, yet December's sun continues to provide a hopeful glimmer, allowing residents to embrace the beauty of winter under a bright sky.
In December, Keystone, United States, enjoys a 53% chance of sunny weather, marking it as a promising winter month. As the year progresses, one can observe a gradual increase in sunshine likelihood, peaking in September at an impressive 65% before tapering off through the fall months. November, with 60%, sets a strong precedent for December's sunny potential. Though the winter chill settles in, December's sunshine chance is relatively high compared to its neighboring months of January and February, which both show lower probabilities of sun. This suggests that while the days may grow shorter, Keystone still offers a balance of clear skies and festive winter charm.
In Keystone, United States, the daylight duration exhibits a fascinating seasonal rhythm. As winter approaches, December brings a return to 9 hours of daylight, mirroring the shorter days of January and November. This period contrasts sharply with the sun-drenched days of late spring and early summer from May to July, when daylight peaks at a generous 14 hours. The gradual transition from winter’s gloom, with its minimal light, to the vibrant brightness of spring emphasizes the region's distinct seasonal changes. As December slips into January, residents can anticipate the slow, yet invigorating, return to longer days, as daylight gradually increases in the months to follow.
As December rolls into Keystone, the average wind speed slightly picks up to 2.9 m/s (6 mph), marking a gentle breeze as winter sets in. This increase comes after a series of relatively low wind speeds throughout the summer months, where calm conditions prevailed, especially in July, when winds dropped to an average of 1.8 m/s (4 mph). Notably, the transition to December showcases a gradual rise from November’s 2.8 m/s, indicating a shift toward cooler and brisker conditions. The trend suggests that as the year draws to a close, Keystone experiences a steady breeze, enough to invigorate the winter landscape while still remaining manageable for outdoor enthusiasts.
The weather in Keystone 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 Keystone and find detailed weather information for every month.
December and January weather share some similarities, particularly in temperature and humidity levels, but exhibit slight differences as well. Both months have averages of -11°C (13°F), but December experiences a slightly wider temperature range, with a maximum of 8°C (47°F) compared to January's peak of 5°C (42°F). Precipitation levels are quite similar, with December receiving 43 mm (1.7 in) and January slightly less at 41 mm (1.6 in), and both months seeing precipitation on about 10 days. Humidity remains high throughout both months, with December at 89% and January just slightly lower at 88%. For more specific insights into January weather, visit Keystone weather in January.
December and February both feature frigid temperatures, but February tends to be slightly warmer on average, with an average temperature of -10°C (14°F) compared to December's -11°C (13°F). While both months experience similar minimum temperatures, February has a marginally higher maximum temperature of 9°C (48°F) compared to December's 8°C (47°F). Precipitation levels rise in February, with 59 mm (2.3 in) falling over 14 days compared to December's 43 mm (1.7 in) across 10 days. Additionally, humidity remains high in both months, with December at 89% and February slightly lower at 87%. For a deeper dive into February conditions, check out this link: Keystone weather in February.
December and March present contrasting winter experiences in terms of temperature and precipitation. December features a colder average temperature of -11°C (13°F) with minimums dropping as low as -29°C (-20°F), while March sees a slight warming trend with an average of -5°C (22°F) and minimums around -25°C (-12°F). Precipitation increases from 43 mm (1.7 in) in December to 67 mm (2.7 in) in March, with rainfall occurring on more days in March (14 days compared to December's 10). Additionally, December has a higher humidity level of 89%, while March's humidity is slightly lower at 81%. For detailed weather insights in March, visit Keystone weather in March.
December and April exhibit notable differences in weather conditions. In December, temperatures can drop as low as -29°C (-20°F), with an average of -11°C (13°F) and a maximum reaching 8°C (47°F). The month typically sees about 43 mm (1.7 in) of precipitation over approximately 10 days, coupled with a high humidity level of 89%. In contrast, April experiences slightly milder conditions, with minimum temperatures around -21°C (-5°F) and an average of -3°C (27°F). The month offers a maximum temperature of 10°C (50°F), along with increased precipitation totaling 78 mm (3.1 in) over 13 days, resulting in lower humidity at 76%. These variations highlight the transition from the deep chill of winter in December to the more temperate early spring conditions of April. For more detailed insights into the weather conditions during this month, check out Keystone weather in April.
December and May present stark contrasts in weather patterns. December is characterized by frigid temperatures, with a minimum of -29°C (-20°F) and an average of -11°C (13°F), while May experiences milder conditions, peaking at a maximum of 17°C (63°F) and an average of 2°C (35°F). Precipitation is also more pronounced in May, totaling 81 mm (3.2 in) over 14 days compared to December's 43 mm (1.7 in) over 10 days. In addition, December's high humidity of 89% creates a cold and damp atmosphere, whereas May's humidity drops to 66%, contributing to a fresher feel. For more details on May weather, check out Keystone weather in May.
December and June present stark contrasts in weather conditions. In December, temperatures can plunge to as low as -29°C (-20°F), with an average of -11°C (13°F) and a maximum of 8°C (47°F), creating a frigid environment. The month also sees high humidity at 89% and approximately 43 mm (1.7 in) of precipitation spread across about 10 days. In stark contrast, June offers milder temperatures, with a minimum of -9°C (15°F), an average of 8°C (46°F), and a maximum that can reach up to 24°C (75°F). Humidity drops significantly to 58%, and rainfall increases slightly to 50 mm (2.0 in) over the same number of days. For a more detailed look at weather patterns, check out Keystone weather in June.
December and July present stark contrasts in weather patterns. In December, temperatures can plummet to a minimum of -29°C (-20°F), with an average of -11°C (13°F) and a maximum reaching just 8°C (47°F). The month is characterized by high humidity at 89% and about 43 mm (1.7 in) of precipitation spread over 10 days. In contrast, July boasts much milder conditions, with temperatures ranging from a minimum of -2°C (28°F) to an average of 11°C (53°F) and a maximum of 23°C (74°F). Precipitation increases to 83 mm (3.3 in) over 15 days, but humidity drops significantly to 52%. For more details on July weather, you can visit Keystone weather in July.
December and August present starkly contrasting weather conditions. In December, temperatures plunge to a minimum of -29°C (-20°F) with an average around -11°C (13°F) and can reach a maximum of 8°C (47°F). The month sees considerable humidity at 89% and experiences precipitation on about 10 days, totaling 43 mm (1.7 in). In contrast, August brings milder weather with minimum temperatures hovering at 0°C (32°F), averages of 11°C (52°F), and maximums reaching 22°C (73°F). Humidity is significantly lower at 56%, and the month has slightly more precipitation—53 mm (2.1 in) over 11 days. For more detailed information, you can check Keystone weather in August.
The weather in December contrasts sharply with that of September. In December, temperatures can plummet as low as -29°C (-20°F) and generally hover around an average of -11°C (13°F), reaching a maximum of 8°C (47°F). This month is characterized by high humidity at 89%, and precipitation occurs on about 10 days, with a total of 43 mm (1.7 in). In comparison, September sees milder conditions, with minimum temperatures around -11°C (13°F) and an average of 7°C (46°F), peaking at 22°C (72°F). Humidity is also notably lower in September at 65%, with similar precipitation levels of 43 mm (1.7 in) over 9 days. For more detailed insights about the weather in September, you can check Keystone weather in September.
In comparing the weather between October and December, we see notable differences in temperature and precipitation. October experiences milder averages, with minimum temperatures around -24°C (-10°F) and maximums reaching 17°C (63°F), while December's temperatures are significantly colder, with averages ranging from -29°C (-20°F) to a maximum of 8°C (47°F). Precipitation in December totals 43 mm (1.7 in) over 10 days, which is slightly less than October's 56 mm (2.2 in) over 9 days. Additionally, December's humidity is higher at 89%, compared to October's 76%. For a more detailed look at October weather, you can visit Keystone weather in October.
In comparing the weather between November and December, December experiences slightly colder temperatures, with an average temperature of -11°C (13°F) compared to November's -7°C (20°F). While the minimum temperatures in both months are quite similar, December's maximum temperature of 8°C (47°F) is marginally lower than November's 10°C (50°F). Precipitation levels are relatively comparable, with December receiving 43 mm (1.7 in) over 10 days, while November sees 41 mm (1.6 in) across 8 days. Additionally, December has a higher humidity level at 89%, compared to November's 82%. For a more detailed look at November's weather, you can visit Keystone weather in November.
As December settles over Keystone, the weather takes a notable turn, characterized by crisp temperatures and increased humidity that sets the stage for a wintry wonderland. Unlike the milder conditions of earlier months, the peak chill can reach a maximum of 8°C, contrasting sharply with the bitingly cold averages and the potential for extremely low nighttime temperatures. While precipitation is frequent, with around ten rainy or snowy days, the sheer volume is manageable, leading to a tranquil yet stunning landscape. This month distinctly marks the transition into the depths of winter, making it a unique time to embrace the beauty of a snow-covered Keystone. For more detailed insights, check out Keystone Climate.