Last updated: February 24, 2025
Experience the enchanting December weather of Sullivans Island, United States, where the coastal charm meets crisp winter air. With an average temperature of 13°C (56°F), daytime highs can reach a pleasant 22°C (72°F), while nights can dip to a brisk 0°C (33°F). The month brings 141 mm (5.6 in) of rainfall spread over 10 days, contributing to the island's lush beauty and vibrant wildlife. Humidity levels hover around 84%, wrapping the landscape in a gentle embrace. Whether you're strolling along the beach or exploring local attractions, December on Sullivans Island offers a refreshing and memorable coastal experience.
In December, Sullivans Island experiences a noticeable chill as temperatures drop, with minimums averaging around 0°C (33°F) and averages resting at 13°C (56°F). The coastal paradise transitions into winter, offering a refreshing contrast to the warmer months. Maximum temperatures still reach a pleasant 22°C (72°F), creating a comfortable atmosphere for outdoor activities. Compared to the milder autumn preceding it, December showcases a clear trend of cooling temperatures, yet retains a pleasant daytime warmth that can entice both locals and visitors to explore the island's natural beauty during the holiday season.
December in Sullivans Island ushers in a notable shift in precipitation patterns, characterized by an average of 141 mm (5.6 in) of rainfall, making it one of the wetter months of the year. While the number of rainy days hovers around 10, mirroring the drier months of November and October, the total precipitation reflects a significant increase, likely due to the winter storms that sweep through the region. This surge in rainfall is a stark contrast to the earlier months, particularly the summer peak in July and August, when precipitation reached their zenith. As the year closes, December not only wraps up a year of distinct weather trends but also sets the stage for the milder, yet consistently wet, winter season ahead.
In December, Sullivans Island experiences a notable rise in humidity, reaching 84%—the highest of the year. This increase follows a consistent trend of elevated humidity levels, particularly in the later months, with November sitting at 82% and July also peaking at 82%. Throughout the year, humidity levels generally linger in the higher range, hovering between 78% and 84%, creating a humid subtropical climate that is characteristic of the region. Interestingly, while January kicks off the year with a high 83% humidity, the months of February through October show a slight dip, stabilizing around 78%–81%. This consistent ebb and flow of humidity reflects Sullivans Island's blend of coastal charm and seasonal variation, making it a place where the air always carries a touch of moisture, especially as the year draws to a close.
As the year comes to a close, the December UV Index in Sullivans Island often dips to 4, signaling a moderate level of sun exposure. This represents a shift from the extreme levels experienced during the summer months, where the index peaked at 12 in July, demanding vigilant sun protection and reducing burn times to just 10 minutes. Throughout the year, the UV Index exhibits a clear pattern, with higher indices in the spring and summer, particularly from March to August. In contrast, winter months like December and January allow for longer safe exposure times of 30 minutes or more, encouraging outdoor activities while still reminding us to be sun-smart. For more detailed insights, visit Sullivans Island UV Index.
UV Risk Categories
December in Sullivans Island welcomes a warm farewell to the year, basking in 220 hours of sunshine. While this is a noticeable dip from the high-summer peak of 345 hours in July, it still offers a beautiful charm, making it ideal for coastal strolls despite the cooler temperatures. As the year progresses, Sullivans Island experiences a gradual increase in daylight hours from January's 190 hours, culminating in the vibrant sunshine of May and June. The trend showcases a delightful dance of daylight, with each season bringing its own unique allure to this picturesque United States destination. Even in December, the sunshine remains a comforting presence, inviting visitors to embrace the island’s tranquil beauty during this cozy month.
December in Sullivans Island presents a moderate likelihood of sunny weather, with a 47% chance of sunshine. This forecast mirrors the cooler winter months, showing a slight dip compared to the preceding months. As we transition from November's 61% chance of sunny days, December offers a more balanced outlook, positioned between the brighter end of the year and the greyer months ahead. Overall, while sunny days may be less frequent than in spring or early fall, December maintains a respectable opportunity for clear skies, inviting residents and visitors alike to relish the milder coastal charm.
In Sullivans Island, the rhythm of daylight throughout the year reveals a captivating seasonal dance. December, like its preceding month, offers 10 hours of daylight, marking a dip that accompanies the onset of winter. As the year unfolds from January to June, daylight steadily increases, peaking at 14 hours in the summer months of June and July, when the island's beauty is bathed in sunlight. Following this vibrant stretch, daylight begins its gradual descent, echoing nature's cycles, with the hours receding each autumn. By November and December, the daylight returns to its wintery norm, inviting cozy gatherings and serene beach walks as the sun tucks away early, reminding us of the delicate balance of light and darkness.
As December rolls in, Sullivans Island experiences a gentle shift in its breezy landscape, with an average wind speed of 4.7 m/s (10 mph). This marks a slight decline from the brisker winds of previous months, particularly November, which boasted a more invigorating pace at 5.0 m/s (11 mph). Throughout the year, wind speeds tend to fluctuate, typically hovering between 4.4 m/s (10 mph) in the summer months and reaching peaks of 5.2 m/s (12 mph) during the spring and early winter. By the time December settles in, the coastal winds mellow significantly, reflecting the island's transition into the calmer embrace of winter, while still offering a refreshing touch for those who venture out to enjoy the serene beachside scenery.
The weather in Sullivans Island 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 Sullivans Island and find detailed weather information for every month.
December and January exhibit some notable differences in weather patterns. December experiences a milder overall temperature range, with a minimum of 0°C (33°F) and an average high of 22°C (72°F). In contrast, January's temperatures can dip lower, reaching a minimum of -5°C (24°F) while maintaining a similar maximum of 21°C (70°F). Precipitation also varies; December sees a higher level at 141 mm (5.6 in) over 10 days, whereas January records less at 66 mm (2.6 in) over 8 days. Humidity levels remain fairly consistent, with December at 84% and January slightly lower at 83%. For more specifics on January weather conditions, check out Sullivans Island weather in January.
In comparing December and February weather, we note a slight increase in temperatures during February, with minimums at 2°C (36°F) compared to December's 0°C (33°F) and an average of 14°C (57°F) versus December's 13°C (56°F). Maximum temperatures are fairly similar, with February reaching 21°C (70°F) and December peaking at 22°C (72°F). Precipitation in February also sees a decrease to 91 mm (3.6 in) across 11 days, compared to December's 141 mm (5.6 in) over 10 days, suggesting a slightly wetter December. Additionally, humidity levels in December are higher at 84%, while February maintains a more comfortable 79%. For more detailed insights, check out Sullivans Island weather in February.
When comparing the weather in December and March, December experiences cooler temperatures, with minimums dipping to 0°C (33°F) and an average of 13°C (56°F). In contrast, March sees slightly warmer conditions, with minimum temperatures starting at 2°C (36°F) and an average of 15°C (60°F). Precipitation levels are notably higher in December, with 141 mm (5.6 in) over approximately 10 days, while March receives less rainfall at 62 mm (2.4 in) over only 7 days. Additionally, December has a higher humidity level of 84% compared to March's 79%. For more details on March weather specifically, visit Sullivans Island weather in March.
December weather tends to be cooler with average temperatures ranging from a minimum of 0°C (33°F) to a maximum of 22°C (72°F). Rainfall is relatively high during this month, with 141 mm (5.6 in) of precipitation over about 10 days, and humidity levels are quite high at 84%. In contrast, April brings milder temperatures with a minimum of 6°C (42°F) and a maximum of 27°C (81°F), averaging 19°C (66°F). The precipitation in April is slightly lower at 105 mm (4.1 in) spread over 8 days, and humidity decreases to 78%. For more detailed information on April weather, you can visit Sullivans Island weather in April.
In December, temperatures in Sullivans Island range from a chilly minimum of 0°C (33°F) to a pleasant maximum of 22°C (72°F), with an average of 13°C (56°F). The month sees considerable precipitation, totaling 141 mm (5.6 in) over about 10 days, accompanied by high humidity levels at 84%. In contrast, May offers a much warmer climate, with minimum temperatures around 12°C (55°F) and maximums reaching up to 31°C (89°F), averaging 23°C (74°F). Precipitation is reduced to 82 mm (3.2 in) across just 8 days, and humidity slightly decreases to 78%. For more details on May weather, you can visit Sullivans Island weather in May.
December and June showcase stark contrasts in weather. In December, temperatures range from a chilly minimum of 0°C (33°F) to a comfortable average of 13°C (56°F), peaking at a pleasant 22°C (72°F). The month experiences significant rainfall, with about 141 mm (5.6 in) distributed over 10 days and a high humidity level of 84%. In contrast, June brings much warmer conditions, with temperatures starting at a milder 18°C (64°F) and reaching an average of 26°C (79°F), peaking at a hot 32°C (90°F). Rainfall is slightly higher in June at 144 mm (5.7 in), but it occurs over more days, totaling 17, with humidity at a lower 78%. For more detailed insights, check out Sullivans Island weather in June.
The weather in December and July presents a striking contrast. December features cooler temperatures, with a minimum of 0°C (33°F) and an average of 13°C (56°F), peaking at 22°C (72°F). It also experiences significant precipitation, totaling 141 mm (5.6 in) over about 10 days, coupled with high humidity at 84%. In contrast, July offers much warmer conditions, with minimum temperatures around 22°C (72°F) and averages reaching 27°C (81°F), while maximum temperatures can soar to 32°C (89°F). July is slightly wetter, with precipitation at 171 mm (6.7 in) occurring over 16 days and a humidity level of 82%. For more insights into July’s weather patterns, check out Sullivans Island weather in July.
December and August present strikingly different weather patterns. In December, temperatures range from a chilly 0°C (33°F) at night to a mild 22°C (72°F) during the day, with an average of 13°C (56°F). This month experiences about 141 mm (5.6 in) of precipitation over 10 days, alongside relatively high humidity at 84%. In contrast, August offers a much warmer climate, with minimum temperatures of 23°C (73°F) and maximums reaching up to 31°C (89°F), averaging around 27°C (81°F). This month is also wetter, with 197 mm (7.8 in) of rain falling over 21 days, and a slightly lower humidity level of 81%. For a closer look at specific conditions during this vibrant summer month, check out the Sullivans Island weather in August.
December and September present contrasting weather patterns. In December, temperatures drop, with a minimum of 0°C (33°F) and an average of 13°C (56°F), peaking at a comfortable 22°C (72°F). The month sees significant rainfall, totaling 141 mm (5.6 in) over about 10 days, paired with relatively high humidity at 84%. In contrast, September is much warmer, with temperatures ranging from a minimum of 16°C (61°F) to an average of 26°C (79°F) and reaching a maximum of 32°C (90°F). Rainfall is more pronounced in September, accumulating to 188 mm (7.4 in) across 14 days, though humidity remains slightly lower at 81%. For a more detailed overview, check out Sullivans Island weather in September.
When comparing the weather in December and October, noticeable differences emerge in temperature and overall climate conditions. December typically experiences cooler temperatures, with a minimum of 0°C (33°F) and a maximum of 22°C (72°F), while October boasts a milder climate, where temperatures range from a minimum of 7°C (46°F) to a maximum of 29°C (85°F). Additionally, October sees less precipitation, averaging 85 mm (3.4 in) over 10 days, compared to December's 141 mm (5.6 in) under similar rainfall frequency. Humidity levels are slightly higher in December at 84%, compared to 78% in October. For a more detailed overview, check out Sullivans Island weather in October.
In December, temperatures tend to cool down slightly compared to November, with a minimum of 0°C (33°F) and an average of 13°C (56°F), whereas November features a higher minimum of 3°C (38°F) and an average of 16°C (62°F). Maximum temperatures also decline, from 26°C (79°F) in November to 22°C (72°F) in December. Additionally, December experiences more precipitation, with 141 mm (5.6 in) over 10 days, compared to November's 103 mm (4.1 in) across 8 days. Humidity remains relatively high in both months, with December at 84% and November at 82%. For a detailed insight into November’s weather patterns, visit Sullivans Island weather in November.
As December settles in on Sullivans Island, the weather experiences a distinct shift compared to other months of the year. The average temperature cools down, offering a mild yet refreshing atmosphere perfect for beach strolls without the summer crowds. While precipitation occurs on about a third of the days, it generally comes as brief showers, allowing you to enjoy the unique beauty of the island even during the rain. Notably, the humidity remains elevated, adding a touch of tropical warmth to the cool coastal air. For those looking to dive deeper into the nuances of the region's weather patterns, you can explore more at Sullivans Island Climate.