Last updated: February 24, 2025
In December, Boston experiences a striking range of temperatures, typically peaking at 18°C (65°F) and plunging to a chilly -19°C (-2°F), with an average of around 0°C (33°F). Alongside these diverse temperatures, the city sees approximately 105 mm (4.1 in) of precipitation over 18 days, resulting in a notably humid environment with levels reaching up to 87%. This dynamic weather pattern creates a vivid winter landscape, punctuated by the contrast of mild days and frosty nights. Whether you’re exploring the festive atmosphere or navigating the wintery chill, December in Boston offers a unique experience for both residents and visitors alike.
In December, Boston winters start to bite, with temperatures showcasing a marked drop as the year draws to a close. With minimums reaching -19°C (-2°F), the city braces for chilly days, while the average temperature hovers around 0°C (33°F), providing a stark contrast to the warmer months. Despite these frosty conditions, daytime highs can still surprise, peaking at about 18°C (65°F), reminding us that winter isn't without its moments of warmth. As the landscape turns to a winter wonderland, the fluctuating temperatures signal the onset of holiday cheer, inviting both residents and visitors to revel in the festive spirit amid the brisk air.
In December, Boston experiences a notable shift in weather as it welcomes the winter season. Precipitation amounts reach 105 mm (4.1 in), making it one of the wetter months of the year, while the 18 days of precipitation indicate a higher frequency of rain and snow compared to previous months. This trend is particularly evident when juxtaposed with the drier September, which had only 9 days of precipitation. As temperatures drop, the city transforms under a blanket of winter weather, with icy rains and occasional snowflakes adding to the charm of the holiday season. December’s moisture levels are significant, contributing to the overall annual precipitation that helps maintain Boston's lush surroundings.
In December, Boston experiences a notable shift in humidity, with levels hovering around 87%. This marks a slight decrease from the preceding months of November and October, both of which had higher humidity levels at 88% and 83%, respectively. The trend throughout the year shows a gradual decline from moist winter conditions, peaking at 91% in January and February, to the drier summer months, where humidity dips to its annual low of 72% in August. As the year closes, December's levels are characteristic of a transitional period, reflecting a return to the winter chill while still retaining a touch of moisture, setting the stage for a brisk yet humid start to the New Year.
As December rolls into Boston, residents can expect a significant drop in UV exposure, with the UV Index reaching a low of 2. This translates to a much safer environment for outdoor activities, designated as a low exposure category, allowing for a burn time of 45 minutes before any risk of skin damage. Following a trend of increasing UV levels from January to October, where the index peaked at 10 during the summer months, December provides a welcome respite. With shorter days and less intense sunlight, this month offers a perfect opportunity for winter strolls without the worry of harsh UV rays. For a detailed look at UV trends throughout the year, check out Boston UV Index.
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In December, Boston experiences a modest 104 hours of sunshine, marking a noticeable dip as the year comes to a close. This decrease is consistent with the overall trend of diminishing daylight that begins in the late fall, following a peak in sunshine during the summer months, where both July and August bask in an impressive 338 hours each. As the city transitions into winter, the contrast is clear; earlier months such as May and June enjoy over 280 hours, providing ample light and warmth. While December's sunlight may feel sparse compared to the vibrant summer days, the seasonal cycle brings its own charm to the city, inviting residents to cozy up and appreciate the beauty of winter's embrace amidst those fleeting sunlit moments.
In December, the likelihood of sunny weather in Boston shows a modest 21% chance, aligning more closely with the colder winter months than the brighter spring and summer seasons. This percentage reflects a gradual decline in sunshine probability as the year draws to a close; for instance, October and November offer slightly better odds, at 28% and 33% respectively. Notably, sunshine opportunities in December are a stark contrast to the more vibrant months of March through May, where the chances exceed 40%. As residents brace for the chill of winter, December's gray skies often set the tone, reminding us that while the holidays may sparkle, the sun remains largely hidden during this time of year.
As December descends in Boston, the city experiences a continuation of the shorter daylight hours characteristic of late autumn, with only 9 hours of daylight. This twilit month marks a stark contrast to the longer days of late spring and summer, where sunlight caresses the city for up to 15 hours. Following a gradual increase from the depths of winter in January and November, December's daylight duration stabilizes, reflecting a consistent pattern of light that begins to extend again as the year progresses. With the first hints of longer days emerging in January, Bostonians can look forward to gradually brighter months ahead, transitioning through the fleeting warmth of spring and into the glorious summer sun.
As December arrives in Boston, the winds pick up, reaching an average speed of 4.5 m/s (10 mph), marking a noticeable increase from the previous months. This trend echoes the city’s seasonal shift; throughout the winter months, wind speeds typically rise, contrasting with the calmer summer breezes that hover around 2.7 m/s (6 mph) in August. November's winds, too, pick up the pace at 4.0 m/s (9 mph), signaling a transition as colder, more dynamic weather patterns take hold. The gusty December air not only invigorates the city’s winter charm but also sets the stage for the blustery months ahead, reminding Bostonians of the powerful nature that characterizes this time of year.
The weather in Boston 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 Boston and find detailed weather information for every month.
In December, temperatures range from a minimum of -19°C (-2°F) to a maximum of 18°C (65°F), with an average of 0°C (33°F). The month experiences 105 mm (4.1 in) of precipitation over 18 days and has a humidity level of 87%. In contrast, January tends to be colder, with temperatures dropping further to a minimum of -21°C (-6°F) and an average of -3°C (27°F), while the maximum is slightly lower at 17°C (63°F). January also sees less precipitation, measuring 87 mm (3.4 in) across 14 days, but humidity increases slightly to 91%. For more detailed information about January weather, you can visit Boston weather in January.
December and February display notable differences in weather patterns despite similar average minimum temperatures. In December, the average temperature hovers around 0°C (33°F), with a maximum of 18°C (65°F), while February's average dips slightly to -2°C (29°F) but can reach a maximum of 20°C (69°F). Precipitation amounts are relatively close, with December receiving 105 mm over 18 days compared to February's 90 mm over 16 days. Humidity levels remain high in both months, but February is slightly higher at 91% compared to December's 87%. For a more detailed look at February's weather dynamics, you can explore Boston weather in February.
December and March present quite distinct weather patterns, despite being close in the calendar year. In December, temperatures can plummet to a minimum of -19°C (-2°F), with an average hovering around 0°C (33°F) and a maximum reaching 18°C (65°F). The month experiences considerable precipitation, amounting to 105 mm (4.1 in) over 18 days, with high humidity levels at 87%. In contrast, March starts with slightly milder minimum temperatures at -18°C (0°F) and an average of 2°C (35°F), peaking at 22°C (72°F). Although it has less precipitation at 80 mm (3.2 in) over 13 days, humidity remains similar at 88%. This transition showcases the shift from winter's chill to the promise of spring. For more detailed insights, check out Boston weather in March.
December and April present contrasting weather patterns, with December often characterized by colder temperatures and a wintry atmosphere. In December, the temperatures can drop to a minimum of -19°C (−2°F) and typically average around 0°C (33°F), while April sees milder conditions, with minimums of -5°C (23°F) and an average of 7°C (45°F). April can reach maximum temperatures up to 28°C (82°F), significantly warmer than December's peak of 18°C (65°F). Precipitation is slightly higher in April, totaling 119 mm (4.7 in) over 15 days, compared to December's 105 mm (4.1 in) over 18 days, and both months exhibit similar humidity levels, with April at 88% and December at 87%. For more details about the weather in Boston during April, visit Boston weather in April.
December and May present stark contrasts in weather patterns. In December, temperatures can plummet to a minimum of -19°C (-2°F), with an average of around 0°C (33°F) and a maximum reaching 18°C (65°F). The month experiences around 105 mm (4.1 in) of precipitation over 18 days, accompanied by high humidity at 87%. In contrast, May features a much milder climate, with minimum temperatures around -2°C (29°F), an average of 14°C (58°F), and maximums soaring to 32°C (89°F). While precipitation is slightly higher at 107 mm (4.2 in), it occurs over fewer days, totaling just 14. Moreover, the humidity is somewhat lower at 82%. For more details on what to expect, check out Boston weather in May.
In December, the weather is marked by significantly colder temperatures, with a minimum of -19°C (-2°F) and an average around 0°C (33°F), compared to June’s milder temperatures that range from a minimum of 5°C (42°F) to an average of 19°C (67°F). December experiences more precipitation, amounting to 105 mm (4.1 in) over 18 days, while June sees slightly less with 89 mm (3.5 in) over 12 days. Additionally, humidity is higher in December at 87%, compared to June’s 79%. This stark contrast highlights the seasonal shift from the chill of winter to the warmth of summer. For more detailed insights, you can check Boston weather in June.
December and July present strikingly different weather patterns. In December, temperatures can plunge as low as -19°C (-2°F), with an average of around 0°C (33°F) and a maximum of 18°C (65°F). The month is characterized by high humidity at 87%, with precipitation occurring on 18 days, totaling 105 mm (4.1 in). In contrast, July offers much milder conditions, with temperatures ranging from a minimum of 11°C (52°F) to a maximum of 33°C (91°F) and an average of 22°C (72°F). Rainfall is slightly more prevalent in July, with 127 mm (5.0 in) over 15 days, but the humidity is lower at 77%. For more details on summer conditions, you can visit Boston weather in July.
December and August present stark contrasts in weather conditions. In December, temperatures can plummet to a minimum of -19°C (—2°F), with an average temperature around 0°C (33°F) and occasional highs reaching 18°C (65°F). The month sees significant precipitation, averaging 105 mm (4.1 in) over 18 days, coupled with high humidity at 87%. Conversely, August boasts much milder temperatures, with minimums around 8°C (47°F), averages of 21°C (70°F), and maximums peaking at 31°C (88°F). Despite slightly less precipitation at 85 mm (3.3 in) over 13 days, the humidity is notably lower at 72%. For a closer look at the weather patterns, you can check Boston weather in August.
In December, temperatures can plummet as low as -19°C (-2°F), with an average around 0°C (33°F) and occasional highs reaching 18°C (65°F). This month is characterized by frequent precipitation, occurring on about 18 days, and high humidity levels averaging 87%. In contrast, September boasts milder temperatures, with a minimum of 3°C (38°F) and a much warmer average of 18°C (64°F), peaking at 31°C (89°F) on some days. Precipitation is less frequent in September, falling on only 9 days and totaling 76 mm (3.0 in), with a lower humidity of 76%. For more details on weather conditions during September, you can check Boston weather in September.
When comparing the weather in December to that of October, notable differences emerge. In December, temperatures range from a frigid minimum of -19°C (−2°F) to a maximum of 18°C (65°F), with an average hovering around 0°C (33°F). In stark contrast, October experiences more moderate conditions, with temperatures ranging from a minimum of 0°C (32°F) to a maximum of 29°C (84°F) and an average of 12°C (54°F). Precipitation also varies; December receives about 105 mm (4.1 in) over 18 days, while October has slightly higher rainfall at 134 mm (5.3 in) across 16 days. Humidity levels are quite similar, with December at 87% and October at 83%. For a more detailed look at October weather, you can check Boston weather in October.
In comparing December and November weather, December is generally colder with an average temperature of 0°C (33°F), while November has a milder average of 4°C (40°F). The temperature extremes also highlight this difference, as December can reach a minimum of -19°C (-2°F), compared to November's minimum of -14°C (8°F). Although both months experience significant precipitation—with December receiving 105 mm (4.1 in) over 18 days and November getting 99 mm (3.9 in) over 15 days—December's higher humidity at 87% indicates a more saturated atmosphere. For more insights into November's climate, you can check Boston weather in November.
As December envelops Boston, the city transforms into a winter wonderland characterized by chilly temperatures that dip significantly compared to the milder fall months. With an average temperature around freezing, residents and visitors alike can expect to bundle up against the cold, as nighttime lows can plunge far below the typical winter averages. This month is also marked by elevated precipitation, with frequent snow sweeping across the landscape, adding a serene touch to the bustling urban backdrop. The high humidity levels contribute to a biting cold that intensifies the winter experience. For those keen on understanding how these shifts affect the city’s overall climate, more insights can be found at Boston Climate.