December Weather in Isabela, Puerto Rico

Last updated: August 31, 2025

Discover the December weather in Isabela, Puerto Rico, where the tropical climate offers a pleasant retreat. With maximum temperatures reaching 30°C (86°F) and an average of 25°C (78°F), the days are warm and inviting. However, night temperatures can drop to a comfortable 23°C (73°F). Precipitation is frequent this month, totaling 43 mm (1.7 in) over 15 days, contributing to the lush landscapes that make Isabela so captivating. The humidity sits at a moderate 76%, creating a refreshing atmosphere that enhances the region’s natural beauty. Embrace the enchanting December vibes in this Caribbean paradise!

December Temperature in Isabela

As December rolls into Isabela, Puerto Rico, the island usher in a delightful taste of warmth during the winter months. With temperatures ranging from a mild 23°C (73°F) as the minimum to a comfortable 30°C (86°F) at its peak, the average temperature settles comfortably at 25°C (78°F). This month offers a subtle shift from the cooler temperatures of late autumn, showcasing a slight gradual increase compared to the preceding months. The warmth creates an inviting atmosphere, perfect for enjoying Isabela's stunning beaches and vibrant local culture. As evening descends, the balmy nights beckon visitors to savor the enchanting ambiance of this tropical paradise.

December Weather in Isabela: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Isabela, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Isabela, December typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec767676777980818181807978
Data source: Temperature data for Isabela 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 Isabela

In December, Isabela, Puerto Rico, experiences a notable shift in precipitation patterns, with an average of 43 mm (1.7 in) of rainfall over approximately 15 days. This marks a decrease compared to the preceding months, particularly from the heavy downpours of September, which recorded a substantial 188 mm (7.4 in), and October's 127 mm (5.0 in). The conditions during December hint at a transition toward the drier season as the year comes to a close, while still retaining some humidity typical of tropical climates. This change encourages a vibrant landscape, setting the scene for both the festive spirit and the lush greenery that characterizes Isabela, despite the reduced rainfall.

December Precipitation Trends in Isabela

The chart displays monthly precipitation patterns in Isabela, 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. In Isabela, December typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec34397266978591971881279943
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Isabela

In Isabela, Puerto Rico, December wraps up the year with a moderate humidity level of 76%, continuing a trend of high humidity observed throughout the months. After a gradual decline from 80% in July and August, humidity stabilizes around the mid-70s in the latter months of the year. This slight decrease reflects the island's tropical climate, which typically experiences peak humidity in the summer. With a resemblance to the preceding months of November (78%) and October (78%), December's humidity signals a persistent, comfortable moisture level, perfect for enjoying the vibrant natural beauty of the island as the year comes to a close.

December Average Humidity in Isabela

This chart illustrates the average monthly humidity levels in Isabela, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Isabela is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%75%74%75%75%77%80%80%79%78%78%76%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Isabela

In December, Isabela, Puerto Rico experiences a UV Index of 8, placing it within the very high exposure category. This shows a slight decline from the extreme levels seen throughout most of the year, where figures often hovered between 11 and 14 from February to May. Despite this decrease, the recommended burn time remains at 15 minutes, underscoring the persistent sun intensity in the region. As one transitions from the intense summer months of June through October, the easing UV levels might make December a more tolerable time for outdoor activities, although vigilance is still advised. For detailed insights about UV exposure throughout the year, you can visit Isabela UV Index.

Maximum UV Index Levels in Isabela for December

The chart shows the monthly maximum UV Index (UVI) for Isabela 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. In December, the maximum UV index in Isabela typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec911131314131313131298
Data source: Isabela 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 Isabela

December in Isabela, Puerto Rico, offers a delightful continuation of the island's abundant sunshine, with an impressive 320 hours of golden rays illuminating the landscape. This month represents a slight increase from November's 298 hours, signaling the onset of a vibrant winter season. As one reflects on the year, it’s clear that the sun manages to shine brighter as the months progress, peaking with 361 hours in both May and July. This trend highlights not only the island's tropical charm but also its appeal as a sunny getaway during the holiday season. Visitors can bask in the warmth while enjoying the lush surroundings, making December an ideal time to experience the beauty of Isabela.

Monthly Sunshine Duration in Isabela: December Highlighted

The December sunshine duration represents the total number of hours Isabela 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.
JanFebMarAprMayJunJulAugSepOctNovDec261h307h347h352h361h352h361h352h316h316h298h320h
Data source: Isabela December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Isabela During December

In Isabela, Puerto Rico, December offers a promising likelihood of sunny weather, with a 69% chance of sunshine that marks a notable increase from the previous months. This trend reflects a shift as the year concludes, moving away from the wetter weeks of the summer and early fall. While October and November display moderate chances of sun at 50% and 64% respectively, December stands out as a significant improvement, suggesting clearer skies and more outdoor opportunities. As locals and visitors anticipate the holiday season, the enhanced likelihood of sun makes this coastal gem an inviting escape during the winter months.

Percentage of Sunny Days in December in Isabela

The chart illustrates the percentage of sunny days in Isabela 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 Isabela experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec54%77%66%50%55%31%47%47%53%50%64%69%
Data source: Isabela December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Isabela in December

In Isabela, Puerto Rico, December marks a return to 11 hours of daylight, a continuation of the shorter days that characterize the late fall and winter months. As the year progresses from January through March, daylight gradually increases, peaking at 13 hours in June and July—the height of summer. This warm season then gives way to a subtle decline in daylight throughout late summer and autumn, with hours reducing back down to 11 hours by November. Interestingly, while December's daylight mirrors that of the preceding winter months, the consistent daylight trend throughout the year showcases Isabela's unique tropical climate, ensuring that residents and visitors can still enjoy ample sunshine even as the days grow shorter.

Average Daylight Hours in Isabela for December

The chart illustrates the variation in daylight duration in Isabela throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 8m11h 32m12h 2m12h 33m12h 59m13h 12m13h 5m12h 42m12h 12m11h 41m11h 14m11h 1m
Data source: Isabela daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Isabela

In December, Isabela, Puerto Rico experiences a refreshing uplift in wind speed, averaging 5.4 m/s (12 mph), marking it as one of the more breezy months of the year. This trend of increased winds follows a gradual increase from the calmer months of October and September, where speeds dip to their lowest, averaging around 3.5 m/s (8 mph). As the year wraps up, December's winds are part of a broader seasonal transition, with the average speeds rising noticeably from the 4.3 m/s (10 mph) seen in November. Overall, it's a time when the island's coastal beauty is accentuated by the invigorating flow of air, inviting both locals and visitors alike to embrace the vibrant outdoor atmosphere.

Average December Wind Speed in Isabela

The chart displays monthly wind speed patterns in Isabela, 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.
JanFebMarAprMayJunJulAugSepOctNovDec5.05.75.13.84.35.15.35.03.73.54.35.4 m/s
Data source: Isabela December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Isabela Compares to Other Months

Weather in Isabela varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Isabela, focusing on differences in temperature, rainfall, humidity, and UV levels.

In December, temperatures typically range from a minimum of 23°C (73°F) to a maximum of 30°C (86°F), creating a warm environment with an average temperature of around 25°C (78°F). The month experiences about 43 mm (1.7 in) of precipitation over roughly 15 days, while the humidity remains steady at 76%.

Conversely, January sees slightly cooler conditions, with minimum temperatures dropping to 20°C (69°F) and a maximum of 29°C (84°F), while still maintaining the same average of 25°C (77°F). Precipitation also decreases to 34 mm (1.3 in) across around 11 days, yet the humidity level remains constant at 76%. For a more detailed insight into January's weather, you can check Isabela weather in January.

In December, temperatures in Isabela typically range from a minimum of 23°C (73°F) to a maximum of 30°C (86°F), with an average temperature of 25°C (78°F). The month also sees about 43 mm (1.7 in) of precipitation spread over 15 days, with humidity levels around 76%. In contrast, February's weather is very similar, featuring a minimum temperature of 21°C (69°F) and the same maximum of 30°C (86°F), while maintaining an average of 25°C (76°F). Precipitation decreases slightly to 39 mm (1.5 in) over just 13 days, and humidity drops to 75%. For more details on the weather during this month, check out Isabela weather in February.

In December, the weather tends to be warm with temperatures ranging from a minimum of 23°C (73°F) to a maximum of 30°C (86°F), and average highs around 25°C (78°F). The month experiences about 43 mm (1.7 in) of precipitation spread over approximately 15 days, resulting in a humidity level of 76%. In comparison, March sees slightly cooler temperatures, with minimums of 21°C (70°F) and maximums of 29°C (84°F), while maintaining the same average temperature of 25°C (76°F). However, March is wetter, receiving 72 mm (2.8 in) of rain over 17 days, with humidity slightly lower at 74%. For more detailed information about March weather, check Isabela weather in March.

In December, the weather features a minimum temperature of 23°C (73°F), with an average and maximum temperature both reaching up to 30°C (86°F). This month experiences about 43 mm (1.7 in) of precipitation over 15 days, accompanied by a humidity level of 76%. In contrast, April maintains similar temperature averages, with a minimum of 22°C (72°F) and a maximum of 30°C (86°F). However, April sees slightly higher precipitation at 66 mm (2.6 in) spread across 14 days, and the humidity is marginally lower at 75%. For more detailed insights into April weather, check out Isabela weather in April.

In comparing the weather of December and May, both months exhibit relatively warm temperatures, with December averaging around 25°C (78°F) and May slightly warmer at 26°C (79°F). December sees a maximum of 30°C (86°F) compared to May’s peak of 31°C (88°F). Precipitation is more pronounced in May, with 97 mm (3.8 in) recorded, versus December's 43 mm (1.7 in), and May also experiences rain on about 19 days compared to December's 15 days. Humidity levels remain similar, at 76% in December and 75% in May, contributing to the overall tropical feel of both months. For more detailed information about the weather conditions in May, you can visit Isabela weather in May.

When comparing the weather in December and June, we see some notable differences. December typically experiences slightly cooler temperatures, with an average of 25°C (78°F) compared to June's warmer average of 27°C (81°F). June tends to be a wetter month as well, with 85 mm (3.3 in) of precipitation over 17 days, whereas December receives only 43 mm (1.7 in) of rainfall across 15 days. Humidity levels are relatively similar, with December at 76% and June slightly higher at 77%. For more detailed information, you can check Isabela weather in June.

In December, the weather is warm with temperatures ranging from a minimum of 23°C (73°F) to a maximum of 30°C (86°F), and an average temperature of around 25°C (78°F). The month experiences about 43 mm (1.7 in) of precipitation over 15 days, with humidity levels at 76%. In contrast, July is slightly warmer, with temperatures ranging from a minimum of 24°C (76°F) to a maximum of 31°C (88°F), and an average of 27°C (81°F). Additionally, July sees more precipitation, totaling 91 mm (3.6 in) over 18 days, coupled with higher humidity at 80%. For more details on the weather in July, visit Isabela weather in July.

In December, the weather in Isabela is characterized by a milder temperature range, with minimums of 23°C (73°F), averaging at 25°C (78°F) and peaking at 30°C (86°F). The month experiences less rainfall, totaling 43 mm (1.7 in) over 15 days, and a relative humidity of 76%. In contrast, August tends to be warmer, with a minimum temperature of 24°C (76°F), an average of 27°C (82°F), and maximums reaching 32°C (89°F). This month also sees significantly more precipitation, with 97 mm (3.8 in) spread over 20 days, and higher humidity at 80%. For more detailed insights into August weather, you can visit Isabela weather in August.

When comparing the weather in December and September, December tends to be slightly cooler with average temperatures ranging from a minimum of 23°C (73°F) to a maximum of 30°C (86°F). In contrast, September experiences warmer conditions with average temperatures between 25°C (77°F) and 31°C (88°F). Moreover, September is significantly wetter, receiving 188 mm (7.4 in) of precipitation over 23 days, while December sees only 43 mm (1.7 in) over 15 days. The humidity levels are relatively similar, with December at 76% and September slightly higher at 79%. For a more detailed look at Isabela's weather during September, you can visit Isabela weather in September.

In comparing the weather conditions of December and October, we see some notable differences. December features a slightly cooler temperature range, with a minimum of 23°C (73°F) and an average of 25°C (78°F), while October experiences temperatures that are a bit warmer, starting at 24°C (76°F) with an average of 27°C (81°F). Despite the warmth, October also sees significantly higher precipitation levels, totaling 127 mm (5.0 in) over 21 days, compared to December's 43 mm (1.7 in) over 15 days. Humidity remains relatively consistent, with December at 76% and October at 78%, only slightly differing. For a detailed look at October's weather, visit Isabela weather in October.

In comparing the weather conditions of December and November, both months exhibit similar overall temperatures, with December showing a slight drop in average temperature from 26°C (79°F) in November to 25°C (78°F) in December. The maximum highs remain consistent at around 30°C (86°F) in both months. However, December experiences significantly less precipitation, with only 43 mm (1.7 in) over 15 days compared to November's 99 mm (3.9 in) over 19 days. Humidity levels are also slightly lower in December at 76% compared to November's 78%. For more on November's weather, you can refer to Isabela weather in November.

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Conclusion: What to Expect From December Weather in Isabela

In December, Isabela experiences a gentle transition from the warmer months, with average temperatures hovering around a comfortable 25°C (78°F). This month marks a notable increase in humidity, reaching 76%, which can create a pleasant yet slightly muggy atmosphere. While the average precipitation of 43 mm (1.7 in) falls over approximately 15 days, it adds a refreshing touch to the landscape, contrasting sharply with the drier conditions of earlier months. If you're planning a visit, be prepared for occasional showers but also for the delightful warmth that makes December a unique and inviting time to enjoy all that Isabela has to offer. For more information about the weather patterns throughout the year, check out Isabela Climate.