December Weather in Key Biscayne, United States

Last updated: February 24, 2025

In Key Biscayne, December offers a delightful blend of warm temperatures and refreshing breezes, with daily highs reaching a pleasant 29°C (84°F) and an average around 22°C (72°F). Despite the inviting warmth, evenings can cool down, dipping to a minimum of 11°C (51°F). This month sees a moderate precipitation amount of 41 mm (1.6 in), scattered over approximately 9 days, contributing to the area's lush greenery. With a humidity level of 81%, visitors can expect a humid tropical experience, perfect for enjoying outdoor activities or relaxing on the beach.

December Temperature in Key Biscayne

In Key Biscayne, December welcomes a mild climate, with temperatures ranging from a minimum of 11°C (51°F) to a pleasant average of 22°C (72°F), peaking at 29°C (84°F). As the year winds down, the weather remains relatively warm, maintaining a consistent trend seen in the preceding months. Notably, compared to the cooler January temperatures, December offers a beautiful transition into winter, where outdoor activities are still inviting. While temperatures gradually start to dip, December remains one of the warmer months, encouraging locals and visitors alike to embrace the sunshine and vibrant coastal lifestyle that Key Biscayne is known for.

December Weather in Key Biscayne: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Key Biscayne, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec707373777982838382807672
Data source: Temperature data for Key Biscayne generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Key Biscayne

In Key Biscayne, December typically brings a moderate level of rainfall, with an average precipitation amount of 41 mm (1.6 in) over approximately 9 days. This marks a noticeable decrease in both total rainfall and frequency of precipitation compared to the preceding months, particularly May through September, which witness significantly higher totals and more frequent rain events. As the year comes to a close, the weather pattern shifts, favoring drier conditions in December, providing residents and visitors alike with clearer skies and more opportunities to enjoy outdoor activities. This transitional month is a reminder of the tropical climate's variability, easing into the drier winter season ahead.

December Precipitation Trends in Key Biscayne

The chart displays monthly precipitation patterns in Key Biscayne, 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.
JanFebMarAprMayJunJulAugSepOctNovDec345031631611721741812031579341
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Key Biscayne

In Key Biscayne, United States, December brings a noticeable return to increased humidity, topping off the year at 81%. This level mirrors the dampness typically experienced in January, signaling a shift as the holiday season commences. Observing the trends throughout the year, humidity gradually decreases from 81% in January, reaching its annual low of 69% in June before gradually rising again. The humidity begins to climb in the latter months; however, the year concludes with a consistency typical of the early winter months. This cyclical pattern showcases the tropical climate's characteristic moisture, ensuring that residents and visitors alike can anticipate a warm, humid atmosphere even in the heart of winter.

December Average Humidity in Key Biscayne

This chart illustrates the average monthly humidity levels in Key Biscayne, 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.
JanFebMarAprMayJunJulAugSepOctNovDec81%80%76%73%71%70%70%72%76%79%80%81%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Key Biscayne

As December arrives in Key Biscayne, the UV Index drops to 6, categorized as high exposure and allowing for a burn time of 25 minutes. This marks a noticeable decline from the peak intensity experienced from April to September, when UV levels soared to 12 or 13 under extreme conditions, demanding shorter exposure times of just 10 minutes. Interestingly, the trend reveals that while winter brings relief from the harshest rays, even in December, sun protection remains essential. For more insights on the UV Index throughout the year, visit Key Biscayne UV Index.

Maximum UV Index Levels in Key Biscayne for December

The chart shows the monthly maximum UV Index (UVI) for Key Biscayne 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.
JanFebMarAprMayJunJulAugSepOctNovDec69101212131212111086
Data source: Key Biscayne 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 Key Biscayne

December in Key Biscayne ushers in a delightful respite from the year’s hustle and bustle, boasting an impressive 290 hours of sunshine. As the year draws to a close, sunlight hours experience a subtle decline from the summer peak of 344 hours in July. However, December shines brightly, offering a comforting embrace of warmth, reminiscent of the earlier months. With a gradual decrease from the summer months, December still provides a generous amount of sunshine, making it an inviting destination for those seeking to relish the remaining glow of the year. The transition from November's 280 hours to December’s sunnier disposition sets the stage for a merry holiday atmosphere, perfect for exploring the scenic beauty and outdoor experiences that Key Biscayne so vibrantly offers.

Monthly Sunshine Duration in Key Biscayne: December Highlighted

The December sunshine duration represents the total number of hours Key Biscayne 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.
JanFebMarAprMayJunJulAugSepOctNovDec226h281h327h336h325h312h344h340h314h305h280h290h
Data source: Key Biscayne December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Key Biscayne During December

December in Key Biscayne brings a delightful surge in sunny weather, with a notable 64% chance of sun. This marks a significant increase compared to the preceding months, especially the sweltering summer, where sunshine is scarce, dropping to a mere 15% in June and 19% in July. As the year winds down, the chance of clear skies not only reflects the seasonal transition but heralds a cozy climate ideal for outdoor activities. Compared to the earlier months of November (40%) and October (44%), December’s sunny forecast stands out, promising a cheerful end to the year in this sunny paradise.

Percentage of Sunny Days in December in Key Biscayne

The chart illustrates the percentage of sunny days in Key Biscayne 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 Key Biscayne experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec42%60%55%55%48%15%19%24%31%44%40%64%
Data source: Key Biscayne December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Key Biscayne in December

As December rolls in, Key Biscayne experiences a steady decline in daylight, offering 10 hours of sun each day. This marks the end of a gradual shift that begins in the summer months, where daylight peaks at 13 hours from May through July. Following this high, the sunlit hours start to wane, decreasing to 12 hours in both August and September, and then tapering off to 11 hours in October and November. With the arrival of winter, daylight remains constant at 10 hours in both December and January, signaling a consistent yet subdued end to the year. This rhythmic ebb and flow of daylight not only shapes the island's natural beauty but also influences the lifestyle of its residents and visitors alike.

Average Daylight Hours in Key Biscayne for December

The chart illustrates the variation in daylight duration in Key Biscayne throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 43m11h 17m12h 1m12h 46m13h 23m13h 42m13h 32m12h 58m12h 15m11h 30m10h 52m10h 33m
Data source: Key Biscayne daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Key Biscayne

In Key Biscayne, December ushers in a gentle breeze, with an average wind speed of 3.4 m/s (8 mph), a slight dip from the slightly brisker conditions of previous months. This trend of decreasing wind velocity is consistent as we move from the warmer months into winter, where winds typically range from 3.1 m/s in July to a peak of 4.9 m/s in February and March. It's a reminder of the island's shifting seasonal rhythm, offering a calm interlude as the year winds down, perfect for leisurely strolls along its picturesque beaches while the soft winds create a soothing backdrop to the holiday season.

Average December Wind Speed in Key Biscayne

The chart displays monthly wind speed patterns in Key Biscayne, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.94.94.94.44.63.93.13.42.43.54.13.4 m/s
Data source: Key Biscayne December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Key Biscayne Compares to Other Months

The weather in Key Biscayne 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 Key Biscayne and find detailed weather information for every month.

December and January in Key Biscayne present a mild tropical climate, though January tends to be slightly cooler. In December, temperatures range from a minimum of 11°C (51°F) to a maximum of 29°C (84°F), while January sees lower minimums at 7°C (44°F) and similar maximums at 28°C (83°F). Precipitation is slightly less in January, with 34 mm (1.3 in) over 6 days compared to December's 41 mm (1.6 in) over 9 days. Both months share a consistent humidity level of 81%, creating a pleasant, albeit humid, atmosphere. For more detailed information, you can visit Key Biscayne weather in January.

December and February in Key Biscayne exhibit mild and pleasant weather patterns, although some subtle differences can be observed. December’s average temperature is slightly cooler, ranging from a minimum of 11°C (51°F) to a maximum of 29°C (84°F), while February shows a more stable range with temperatures averaging between 10°C (51°F) and 28°C (83°F). Precipitation is more pronounced in February, with 50 mm (2.0 in) expected over 9 days compared to December's 41 mm (1.6 in) under the same number of rainy days. Humidity levels are quite similar in both months, with December at 81% and February slightly lower at 79%. For more detailed insights, you can explore Key Biscayne weather in February.

In comparing the weather of December and March, December presents slightly cooler temperatures, with a minimum of 11°C (51°F) and an average of 22°C (72°F), while March enjoys a slightly warmer minimum of 12°C (54°F) and an average of 23°C (73°F). The maximum temperatures also show a minor increase, with December peaking at 29°C (84°F) compared to March's 30°C (86°F). Furthermore, December experiences more precipitation, averaging 41 mm (1.6 in) over about 9 days, whereas March has a lower total of 30 mm (1.2 in) across only 5 days. Humidity levels are also a bit higher in December at 81%, compared to 76% in March. For a more detailed look at March weather, you can visit Key Biscayne weather in March.

In comparing the weather of December and April, we see a noticeable shift in temperature and precipitation patterns. December presents a milder climate, with minimum temperatures around 11°C (51°F) and average highs of 22°C (72°F), while April is noticeably warmer, featuring minimum temperatures of 15°C (59°F) and an average maximum of 25°C (77°F). Additionally, April experiences higher precipitation, with about 63 mm (2.5 in) spread over 11 days, compared to December's 41 mm (1.6 in) over 9 days. The humidity remains relatively high in both months, though slightly lower in April at 73% compared to December's 81%. For more detailed insights, you can explore Key Biscayne weather in April.

In December, Key Biscayne experiences milder temperatures with a minimum of 11°C (51°F) and an average of 22°C (72°F), while May sees significantly warmer conditions, starting at a minimum of 19°C (66°F) and averaging 26°C (79°F). December is characterized by lower humidity at 81%, but it does have a modest amount of precipitation, averaging 41 mm (1.6 in) over about 9 days. In contrast, May is wetter, with 161 mm (6.3 in) of rain spread across 18 days, though the humidity is lower at 71%. For a more detailed overview, you can view the seasonal variability here: Key Biscayne weather in May.

When comparing the weather in December and June, it's evident that June brings higher temperatures and significantly more rainfall. December features a mild temperature range with a minimum of 11°C (51°F) and a maximum of 29°C (84°F), averaging around 22°C (72°F), while June's temperatures are considerably warmer, with a minimum of 24°C (75°F) and a maximum of 32°C (90°F), averaging 28°C (82°F). Additionally, December experiences about 41 mm (1.6 in) of precipitation over 9 days, whereas June sees a much wetter climate with 172 mm (6.8 in) of rainfall across 22 days. The humidity in December is high at 81%, contrasting with June's lower humidity level of 69%. For more detailed information, you can check Key Biscayne weather in June.

When comparing the weather in December and July, significant differences emerge. December experiences milder temperatures, with a minimum of 11°C (51°F) and a maximum of 29°C (84°F), providing comfortable averages around 22°C (72°F). In contrast, July is notably warmer, with temperatures ranging from a minimum of 24°C (76°F) to a high of 33°C (92°F), averaging 28°C (83°F). Furthermore, July sees significantly more precipitation at 173 mm (6.8 in) over 26 days compared to December’s 41 mm (1.6 in) across only 9 days, although it has lower humidity at 70% compared to December's 81%. For more details on July weather specifics, you can check out Key Biscayne weather in July.

In December, the weather is milder with temperatures ranging from a minimum of 11°C (51°F) to a maximum of 29°C (84°F), providing an average of 22°C (72°F). Rainfall during this month is relatively low, with only 41 mm (1.6 in) recorded over 9 days, and humidity is high at 81%. In contrast, August experiences much warmer temperatures, with a minimum of 25°C (76°F) and a maximum of 32°C (90°F), resulting in an average temperature of 28°C (83°F). However, August is significantly wetter, accruing 181 mm (7.1 in) of precipitation over 25 days, while humidity is lower at 72%. For more details, check out Key Biscayne weather in August.

When comparing the weather between December and September, December offers milder temperatures, with a minimum of 11°C (51°F) and an average of 22°C (72°F), while September experiences warmer conditions, with a minimum of 24°C (75°F) and an average of 28°C (82°F). Precipitation is notably higher in September, averaging 203 mm (8.0 in) over 22 days, compared to December's 41 mm (1.6 in) across just 9 days. Humidity levels remain relatively high in both months, with December at 81% and September slightly lower at 76%. For more details on the conditions in September, visit Key Biscayne weather in September.

When comparing the weather in December and October, December is generally milder with average temperatures ranging from a minimum of 11°C (51°F) to a maximum of 29°C (84°F), while October features higher average temperatures, peaking at 30°C (87°F) with a minimum of 15°C (59°F). Precipitation also varies significantly; December sees 41 mm (1.6 in) of rain over about 9 days, whereas October experiences a much wetter atmosphere with 157 mm (6.2 in) over 22 days. Humidity levels are similar, with December at 81% and October slightly lower at 79%. For more detailed insights into October's weather, you can visit Key Biscayne weather in October.

December weather in Key Biscayne features a slight decrease in temperature, with average highs of 29°C (84°F) compared to November's 30°C (86°F). Humidity remains relatively constant between the two months, with December at 81% and November at 80%. However, December experiences significantly less precipitation, measuring just 41 mm (1.6 in) over 9 days, while November sees much heavier rainfall at 93 mm (3.7 in) over 14 days. For more detailed information, you can check out Key Biscayne weather in November.

Compare Key Biscayne's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Key Biscayne

As December ushers in the winter season, Key Biscayne experiences a delightful shift in weather compared to the balmy summer months. With comfortable average temperatures hovering around 22°C (72°F), the island offers a refreshing respite from the heat. While occasional precipitation occurs—with about nine rainy days this month—the overall humidity remains high, enhancing the tropical atmosphere. This pleasant climate makes December an ideal time to explore the beautiful beaches and vibrant surroundings. For a deeper understanding of what to expect throughout the year, check out the detailed insights at Key Biscayne Climate.