December Weather in Mount Vernon, United States

Last updated: February 24, 2025

In Mount Vernon, United States, December brings a chill with average temperatures hovering around 5°C (42°F), occasionally peaking at a comfortable 20°C (69°F) but often plunging to lows of -10°C (14°F). The month experiences notable precipitation, accumulating 89 mm (3.5 in) over about 9 days, contributing to the region's 84% humidity. This blend of crisp air and damp conditions creates a quintessential winter atmosphere, ideal for seasonal festivities and cozy indoor gatherings.

December Temperature in Mount Vernon

In December, Mount Vernon experiences a notable chill, with minimum temperatures dipping to around -10°C (14°F). As winter sets in, the average temperature hovers at 5°C (42°F), providing a brisk atmosphere ideal for cozy indoor activities. Daytime highs can reach a comfortable 20°C (69°F), a pleasant contrast against the colder nights. This month marks a transition from the crisp autumnal coolness of November, where temperatures can still be relatively mild, to the fuller embrace of winter. The shift underscores a broader trend of decreasing temperatures as the year draws to a close, inviting residents and visitors alike to bundle up and enjoy the festive season amidst the scenic winter landscape.

December Weather in Mount Vernon: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Mount Vernon, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec374247576776817872634841
Data source: Temperature data for Mount Vernon 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.

December Precipitation in Mount Vernon

In December, Mount Vernon experiences a striking blend of rainfall, with precipitation amounting to 89 mm (3.5 in) spread over approximately 9 days. This month typically sees a dip in moisture compared to the height of summer, where July and August peak at 132 mm and 146 mm, respectively. However, December's totals are notable in their consistency, falling in line with the wetter months that precede it. As the year closes, the cool embrace of winter is accompanied by a moderate yet steady drizzle, creating a refreshing environment just before the dry season begins. This trend of fluctuating precipitation throughout the year underscores Mount Vernon's diverse climatic patterns, highlighting how each month contributes uniquely to the region’s overall weather narrative.

December Precipitation Trends in Mount Vernon

The chart displays monthly precipitation patterns in Mount Vernon, 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.
JanFebMarAprMayJunJulAugSepOctNovDec619682102121108132146931057789
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Mount Vernon

December in Mount Vernon sees a relative humidity of 84%, marking a slight decrease from the previous month's high of 85%. Throughout the year, humidity levels exhibit a noticeable trend; they tend to be highest in the winter months, peaking in November, before slightly tapering in December. As the colder months progress, the humidity remains relatively high compared to the summer months, where July and August experience the driest conditions at 74% and 72%, respectively. This seasonal fluctuation highlights Mount Vernon's characteristic damp winters, a contrast to its warmer, more arid summer climate. The consistent humidity levels in December contribute to the region's cool and sometimes brisk atmosphere, embodying the essence of winter in this charming locale.

December Average Humidity in Mount Vernon

This chart illustrates the average monthly humidity levels in Mount Vernon, with December's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how December's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec84%83%83%81%78%79%74%72%75%81%85%84%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Mount Vernon

In Mount Vernon, December marks the onset of winter with a UV Index of 3, indicating a moderate level of sun exposure that allows for a burn time of approximately 30 minutes. As we look back at the year, a noticeable trend emerges: from January to March, UV levels gradually increase, peaking in the summer months of May through July at a striking 10, categorized as very high, with just 15 minutes of burn time. This is followed by a steady decline into the cooler months, where both October and November reflect a more moderate exposure before settling into the gentle winter conditions of December. Awareness of these fluctuations is essential for effective sun protection practices throughout the year. For more details, visit the Mount Vernon UV Index.

Maximum UV Index Levels in Mount Vernon for December

The chart shows the monthly maximum UV Index (UVI) for Mount Vernon 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.
JanFebMarAprMayJunJulAugSepOctNovDec357910101098753
Data source: Mount Vernon 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.

December Sunshine in Mount Vernon

In Mount Vernon, December brings a gentle retreat from the sunniest months of the year, offering 190 hours of daylight. This marks a noticeable decline from the peak of 357 hours in July, highlighting a seasonal shift as the winter solstice approaches. However, December’s sunshine still outshines the earlier winter months, providing more hours than November’s 226. As the year closes, the gradual decrease in sunlight is a reminder of nature's rhythm, transitioning from the vibrant brightness of summer to the serene beauty of winter. This lingering daylight offers residents a chance to embrace the holiday spirit, making the most of every sunlit moment before the long nights of January arrive.

Monthly Sunshine Duration in Mount Vernon: December Highlighted

The December sunshine duration represents the total number of hours Mount Vernon experiences direct sunlight during the month of December, excluding cloudy or obstructed periods. This chart compares the sunshine duration of December with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec153h180h259h259h286h331h357h321h276h249h226h190h
Data source: Mount Vernon December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Mount Vernon During December

In December, Mount Vernon experiences a 39% chance of sunny weather, marking a noticeable dip as winter settles in. This trend follows an upward trajectory in the latter months of the year, with November peaking at 58%, making it the sunniest month just before the year's end. Interestingly, while December fares better than some summer months like June (39%) and August (35%), it contrasts sharply with the vibrant sunshine typical in March (52%) and September (55%). Overall, December’s sun exposure tends to be on the lower side, highlighting the transition into the colder months when cloudy and rainy conditions become more frequent.

Percentage of Sunny Days in December in Mount Vernon

The chart illustrates the percentage of sunny days in Mount Vernon throughout the year, with December 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 Mount Vernon experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec46%29%52%49%40%39%49%35%55%41%58%39%
Data source: Mount Vernon December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Mount Vernon in December

In Mount Vernon, December brings a return to the shorter daylight hours, with just 9 hours of sunlight to brighten the winter days. This is consistent with the trend observed throughout the year, where daylight begins at 9 hours in January, gradually increasing to a peak of 14 hours during the summer months of June, July, and August. As autumn approaches, daylight gradually dwindles, tapering down to 10 hours in November before hitting its lowest point in December. This cyclical pattern illustrates the seasonal rhythm of sunlight in Mount Vernon, offering a gentle reminder of the vibrant longer days ahead as winter transitions into spring.

Average Daylight Hours in Mount Vernon for December

The chart illustrates the variation in daylight duration in Mount Vernon throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 47m10h 45m11h 58m13h 14m14h 18m14h 49m14h 32m13h 35m12h 23m11h 8m10h 2m9h 29m
Data source: Mount Vernon daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Mount Vernon

As December settles over Mount Vernon, the average wind speed hovers at a gentle 2.8 m/s (6 mph), echoing the calmness of the season. This slight decline from the months preceding it aligns with a broader trend of diminishing winds that stretches from the summer, where July's breezes were the softest at just 2.3 m/s (5 mph). Interestingly, December remains relatively stable, maintaining a consistent airflow similar to November's. Throughout the year, spring and early winter months showcased a brisker atmosphere, with sustained speeds of 3.2 m/s (7 mph) from January through April. The shift towards milder winds in December heralds a transition, inviting cozy moments by the fire as the landscape gracefully transforms into a winter wonderland.

Average December Wind Speed in Mount Vernon

The chart displays monthly wind speed patterns in Mount Vernon, with values for each month shown alongside December's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how December's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.93.23.23.22.82.52.31.92.52.72.92.8 m/s
Data source: Mount Vernon December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Mount Vernon Compares to Other Months

The weather in Mount Vernon 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 Mount Vernon and find detailed weather information for every month.

December and January exhibit notable differences in weather patterns. In December, temperatures range from a minimum of -10°C (14°F) to a maximum of 20°C (69°F), with an average temperature of 5°C (42°F). The month experiences significant precipitation of 89 mm (3.5 in) over 9 days, maintaining a consistent humidity level of 84%. In contrast, January is slightly colder, with temperatures dipping to a minimum of -14°C (7°F) and an average of 3°C (38°F), while reaching a maximum of 22°C (71°F). Precipitation decreases to 61 mm (2.4 in) over 7 days, yet humidity remains constant at 84%. For more detailed information on January weather, check out Mount Vernon weather in January.

In December, the weather experiences a milder average temperature of 5°C (42°F), with minimums dropping to -10°C (14°F) and maximums reaching 20°C (69°F). The month sees around 89 mm (3.5 in) of precipitation over approximately 9 days, accompanied by high humidity levels at 84%. Conversely, February brings even colder conditions, with minimum temperatures dipping to -14°C (7°F) while still averaging 5°C (42°F) and reaching maximums of 27°C (81°F). Precipitation slightly increases to 96 mm (3.8 in) over 11 days, while humidity remains relatively stable at 83%. For a more detailed look at February weather trends, check out Mount Vernon weather in February.

In December, temperatures range from a chilly -10°C (14°F) at their lowest to a mild maximum of 20°C (69°F), averaging around 5°C (42°F). The month experiences higher humidity at 84% and sees around 89 mm (3.5 in) of precipitation over 9 days. In contrast, March brings slightly warmer temperatures, with a minimum of -6°C (22°F) and a maximum of 29°C (84°F), resulting in an average temperature of 8°C (47°F). Precipitation decreases slightly to 82 mm (3.2 in) yet remains consistent with 9 days of rain, and humidity is marginally lower at 83%. For those interested in more specific details about the weather in March, visit Mount Vernon weather in March.

In December, the weather is quite chilly, with temperatures ranging from a minimum of -10°C (14°F) to an average of 5°C (42°F) and peaking at 20°C (69°F). The month experiences considerable precipitation at 89 mm (3.5 in) over approximately 9 days, accompanied by high humidity levels at 84%.

In contrast, April showcases a significant warming trend, with temperatures ranging from a minimum of -1°C (31°F) to an average of 14°C (58°F) and a maximum of 33°C (92°F). The precipitation increases slightly to 102 mm (4.0 in) over 11 days, but the humidity is marginally lower at 81%. For more details on the climate during this transition to spring, you can check Mount Vernon weather in April.

December and May present notably contrasting weather experiences. In December, temperatures range from a chilling minimum of -10°C (14°F) to a mild maximum of 20°C (69°F), averaging around 5°C (42°F). This month sees substantial precipitation of 89 mm (3.5 in) over about 9 days, paired with high humidity levels at 84%. In stark contrast, May enjoys warmer temperatures with a minimum of 3°C (37°F) and a maximum soaring to 35°C (95°F), averaging 19°C (67°F). The month also experiences slightly higher precipitation at 121 mm (4.8 in) but over more days—12 in total—resulting in a lower humidity of 78%. For more detailed weather information specific to May, check out Mount Vernon weather in May.

December and June present stark contrasts in weather, reflecting the seasonal shift from winter to summer. In December, temperatures can drop as low as -10°C (14°F) and average around a chilly 5°C (42°F), with maximums reaching only 20°C (69°F). The month experiences significant precipitation, measuring 89 mm (3.5 in) over about 9 days, and the humidity is quite high at 84%. In contrast, June showcases a much warmer climate, with minimum temperatures of 9°C (49°F) and averages soaring to 24°C (76°F), peaking at a startling 37°C (98°F). Although June sees slightly higher precipitation levels at 107 mm (4.2 in) over 13 days, the humidity is somewhat lower at 79%. For a more detailed look at the weather specifics during this vibrant month, visit Mount Vernon weather in June.

When comparing the weather in December and July, it's clear that these months have significantly different characteristics. December experiences colder temperatures, with an average of 5°C (42°F) and minimums dropping as low as -10°C (14°F). In contrast, July is much warmer, boasting an average temperature of 27°C (81°F) and maximums reaching up to 38°C (102°F). Additionally, December sees a higher humidity level at 84% compared to July's 74%, despite July having slightly more precipitation at 132 mm (5.2 in) over 12 days versus December's 89 mm (3.5 in) across 9 days. For more detailed information on the warm summer weather, you can visit Mount Vernon weather in July.

When comparing the weather in December and August, notable differences emerge in temperature and conditions. December experiences cooler temperatures, with a minimum of -10°C (14°F) and an average of 5°C (42°F), whereas August boasts much warmer temperatures, ranging from a minimum of 15°C (59°F) to an average of 25°C (78°F). Precipitation is more frequent in August, with 15 days of rain totaling 146 mm (5.7 inches), compared to December's 9 days and 89 mm (3.5 inches). Additionally, December has a higher humidity level of 84%, while August's humidity sits at 72%, making the latter feel more comfortable despite the heat. For a detailed look at August conditions, check out Mount Vernon weather in August.

The weather in December contrasts sharply with that of September, showcasing a significant drop in temperatures and an increase in precipitation. In December, temperatures range from a chilly minimum of -10°C (14°F) to a maximum of 20°C (69°F), averaging around 5°C (42°F), while September enjoys a much warmer climate, with temperatures peaking at 37°C (99°F) and averaging 22°C (73°F). Precipitation is slightly higher in September at 93 mm (3.7 in) over 11 days compared to December’s 89 mm (3.5 in) across 9 days. Additionally, the humidity in December is notably higher at 84%, in contrast to the more comfortable 75% observed in September. For more detailed insights, you can check Mount Vernon weather in September.

In comparison to October, December presents significantly cooler temperatures, with a minimum of -10°C (14°F) and an average of 5°C (42°F), while October enjoys milder weather with a minimum of 2°C (36°F) and an average of 17°C (63°F). Throughout both months, there is a similar number of rainy days—9 days—although December sees slightly less precipitation at 89 mm (3.5 in) compared to October's 105 mm (4.2 in). Additionally, humidity levels are high in both months, with December at 84% and October at 81%. For more detailed information about October weather in the area, you can visit Mount Vernon weather in October.

December experiences cooler temperatures compared to November, with minimums dipping to -10°C (14°F) and a lower average of 5°C (42°F), while November has a milder minimum of -5°C (23°F) and an average of 9°C (48°F). Despite both months having similar humidity levels, December sees increased precipitation at 89 mm (3.5 in) over 9 days, compared to November's 77 mm (3.0 in) over 7 days. Furthermore, while November can reach a maximum temperature of 26°C (78°F), December's maximum only reaches up to 20°C (69°F). For more details on the weather patterns specific to November, check out Mount Vernon weather in November.

Compare Mount Vernon's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Mount Vernon

As December settles in Mount Vernon, residents experience a striking shift in weather compared to the milder months preceding it. The chill of winter becomes palpable with average temperatures dipping significantly, bringing an air of crispness and occasional frost. While the month sees ample rainfall, the humidity lingers at a high level, enhancing the feeling of cold. Unlike the balmy autumn days, December often wraps the landscape in a serene, chilly embrace. Whether you're enjoying the festive season or preparing for winter's onslaught, keep in mind how these weather patterns shape the charm of this month. For more insights into the climate throughout the year, explore Mount Vernon Climate.