September Weather in Culebra, Puerto Rico

Last updated: August 31, 2025

September in Culebra, Puerto Rico brings warm, tropical weather characterized by maximum temperatures reaching 29°C (85°F) and an average of 28°C (82°F), with a mild minimum of 25°C (78°F). This month is also marked by significant precipitation, totaling around 160 mm (6.3 inches) over 20 rainy days, making it one of the wetter periods of the year. With an average humidity level of 79%, visitors can expect balmy conditions that contribute to the lush vegetation and vibrant landscapes typical of this enchanting island. Despite the rain, the island’s natural beauty remains inviting, offering a unique blend of sunshine and tropical showers that define September's allure.

September Temperature in Culebra

In September, Culebra, Puerto Rico, embraces a warm embrace with temperatures ranging from a minimum of 25°C (78°F) to a cozy maximum of 29°C (85°F). This month mirrors the summer's lingering warmth, with an average temperature settling at 28°C (82°F), making it a perfect time for beach lovers and sun-seekers to soak up the sun. As the island transitions toward autumn, the days remain invitingly warm, with nighttime temperatures still comfortable, ensuring pleasant evenings by the shore. Overall, September's climate showcases a continuation of the tropical warmth that characterizes Culebra throughout the year, providing a delightful backdrop for adventure and relaxation.

September Weather in Culebra: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Culebra, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Culebra, September 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).
JanFebMarAprMayJunJulAugSepOctNovDec787777787981818282818079
Data source: Temperature data for Culebra 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.

September Precipitation in Culebra

September is a notably wet month in Culebra, Puerto Rico, with an impressive 160 mm (6.3 in) of rainfall spread across 20 days. This significant precipitation marks a sharp increase from the preceding months, peaking after a steady rise through the summer. Comparatively, August averages 114 mm (4.5 in) over the same number of rain days, suggesting that September's downpours often intensify as the region transitions fully into the rainiest part of the year. This pattern underscores the island's vulnerability to wetter weather, making September a crucial month for understanding local climatic trends and preparing for the potential challenges of tropical storms. As the year progresses into October, Culebra witnesses a slight decrease in rainfall, but the lingering effects of September's humidity can still be felt.

September Precipitation Trends in Culebra

The chart displays monthly precipitation patterns in Culebra, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Culebra, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec33314041576410211416013610751
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Culebra

In Culebra, Puerto Rico, September experiences an average humidity level of 79%, slightly lower than the peak months of July and August, which both hover around 80%. The humidity tends to rise during the summer months, showcasing an upward trend from June's 77% to August. Following the peak of summer, September marks the beginning of a gradual decline as the island transitions into the cooler months. Humidity levels remain relatively stable throughout the year, fluctuating between 74% in March and 80% in July and August, indicating a consistent tropical climate. This enduring humidity, while often high, does not deter the island's charm, inviting visitors to bask in its natural beauty year-round.

September Average Humidity in Culebra

This chart illustrates the average monthly humidity levels in Culebra, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Culebra 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 September generated using information from the Copernicus Climate Change Service.

September UV Index in Culebra

In September, Culebra, Puerto Rico experiences a notably high UV Index of 14, placing it firmly in the extreme exposure category. This marks a peak in sun intensity, following a summer where UV levels ranged consistently from 12 to 13. With a recommended burn time of just 10 minutes, beachgoers and outdoor enthusiasts must be particularly vigilant about sun protection during this month. The trend is clear: as the calendar shifts from summer to autumn, the UV Index remains unforgivingly high, urging everyone to take extra precautions. For more detailed information on the UV Index throughout the year, visit Culebra UV Index.

Maximum UV Index Levels in Culebra for September

The chart shows the monthly maximum UV Index (UVI) for Culebra in September, 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 September, the maximum UV index in Culebra typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec911131313131213141298
Data source: Culebra September 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.

September Sunshine in Culebra

As summer winds down, September in Culebra, Puerto Rico, continues to bask in a generous 319 hours of sunshine. This month witnesses a subtle decline from the sun-kissed peaks of summer, with May and July leading the way at 358 and 354 hours, respectively. However, September's radiant skies still offer a vibrant contrast to the upcoming autumn, maintaining a steady brightness that ensures beach-goers and adventurers alike can enjoy the warm tropical days. The slight dip in sunshine hours compared to the previous months indicates a gentle transition, yet it remains ample for soaking up the beauty of Culebra’s stunning landscapes. With October following closely behind with 316 hours, the trend signals that while the summer may be fading, the spirit of sun-soaked days endures in this idyllic paradise.

Monthly Sunshine Duration in Culebra: September Highlighted

The September sunshine duration represents the total number of hours Culebra experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec258h301h349h348h358h344h354h347h319h316h302h320h
Data source: Culebra September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Culebra During September

September in Culebra, Puerto Rico, offers a pleasantly moderate 57% chance of sunny weather, making it a favorable time for beachgoers and outdoor enthusiasts. As summer winds down, the likelihood of sunshine sees a subtle uptick compared to the dreary summer months of June (24%) and July (47%), though it’s still below the highs of the earlier months like February (73%) and March (71%). This blend of cloud cover and sunshine can create an ideal atmosphere for exploring the island, as the overall trend suggests September strikes a balance between the lingering warmth of summer and the onset of fall, leading to enjoyable yet less predictable weather patterns. With this moderate chance of sun, visitors can expect a mix of sunny days and occasional clouds, perfect for both relaxation and adventure in this tropical paradise.

Percentage of Sunny Days in September in Culebra

The chart illustrates the percentage of sunny days in Culebra throughout the year, with September 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 Culebra experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec56%73%71%51%62%24%47%44%57%53%66%70%
Data source: Culebra September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Culebra in September

In Culebra, Puerto Rico, September offers a delightful 12 hours of daylight, seamlessly continuing the trend observed in the previous summer months of June and July. The transition from the peak summer brightness slowly shifts towards the shorter days of fall, with daylight duration stabilizing at 12 hours from April through September. As the year progresses, daylight begins to wane, with October witnessing a dip to 11 hours. This rhythmic ebb and flow of daylight not only enhances the island's enchanting landscapes but also sets a perfect backdrop for exploring Culebra’s breathtaking beaches and vibrant marine life as summer fades into fall.

Average Daylight Hours in Culebra for September

The chart illustrates the variation in daylight duration in Culebra throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 9m11h 32m12h 2m12h 33m12h 59m13h 11m13h 5m12h 42m12h 12m11h 41m11h 15m11h 2m
Data source: Culebra daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Culebra

In September, the winds in Culebra, Puerto Rico begin to mellow, with an average speed of only 5.5 m/s (12 mph), marking the calmest month of the year. This gentle breeze contrasts sharply with the stronger winds of the preceding summer months, where July and August clocked in at 8.4 m/s (19 mph) and 7.4 m/s (17 mph), respectively. As the high summer transitions to autumn, these lighter winds create a serene atmosphere, perfect for those looking to enjoy the tranquility of the island. Interestingly, as the year progresses, October sees a slight uptick in wind speed to 6.1 m/s (14 mph), hinting at the return of the breezy conditions that characterize much of the rest of the year.

Average September Wind Speed in Culebra

The chart displays monthly wind speed patterns in Culebra, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec6.98.77.56.37.18.18.47.45.5 m/s6.16.47.8
Data source: Culebra September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Culebra Compares to Other Months

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

September and January exhibit distinct differences in weather patterns. September is characterized by warmer temperatures, with minimums around 25°C (78°F) and averages reaching up to 28°C (82°F), while January sees slightly cooler conditions, with averages of 25°C (78°F) and maximums of 27°C (81°F). Additionally, September experiences significantly more rainfall, with 160 mm (6.3 in) over 20 days compared to January's much drier conditions of 33 mm (1.3 in) over 13 days. Humidity levels are relatively high in both months, but September's average of 79% is slightly higher than January's 76%. For more detailed information, check out Culebra weather in January.

September and February exhibit notable differences in weather conditions. In September, temperatures are generally warmer, with an average of 28°C (82°F) and a maximum of 29°C (85°F). This month also sees significant rainfall, with precipitation reaching 160 mm (6.3 in) over about 20 days and humidity levels peaking at 79%. In contrast, February experiences milder temperatures, with an average of 25°C (77°F) and a maximum of 27°C (81°F). Rainfall is considerably lower in February, totaling only 31 mm (1.2 in) over 12 days, and humidity is slightly less at 75%. For more detailed information, check out Culebra weather in February.

In comparing the weather of September and March, September tends to be significantly warmer and wetter. With average temperatures reaching 28°C (82°F) and maximums of 29°C (85°F), September experiences a higher minimum temperature of 25°C (78°F). Additionally, it sees more precipitation, totaling 160 mm (6.3 in) over about 20 days, which makes for a more humid environment at 79%. In contrast, March is milder, with average temperatures of 25°C (77°F) and maximums peaking at 26°C (80°F). The month registers only 40 mm (1.6 in) of rain across 11 days, leading to lower humidity at 74%. For a more detailed insight into March weather, you can visit Culebra weather in March.

When comparing the weather in September and April, notable differences emerge. September boasts higher temperatures, with a minimum of 25°C (78°F) and an average of 28°C (82°F), while April has slightly cooler temperatures, ranging from a minimum of 23°C (73°F) to an average of 26°C (78°F). Additionally, September experiences significantly more precipitation, with 160 mm (6.3 in) over approximately 20 days, compared to April's 41 mm (1.6 in) over just 9 days. Humidity levels are also slightly higher in September at 79%, compared to April's 75%. For more details on April weather, you can visit Culebra weather in April.

In comparing the weather of September and May, September tends to be warmer and much wetter. In September, temperatures range from a minimum of 25°C (78°F) to a maximum of 29°C (85°F), with an average of 28°C (82°F) and a substantial precipitation of 160 mm (6.3 inches) spread over 20 days. In contrast, May offers slightly cooler temperatures, with a minimum of 24°C (75°F) and a maximum of 28°C (83°F), averaging around 26°C (80°F). The rainfall in May is significantly lower at 57 mm (2.2 inches) over 13 days, making it a relatively drier month with lower humidity levels at 75%. For a more detailed look at May weather, check out Culebra weather in May.

In comparing the weather between September and June, both months exhibit warm temperatures, with September being slightly warmer on average. September features a minimum temperature of 25°C (78°F) and an average of 28°C (82°F), while June starts at 24°C (76°F) and averages 27°C (81°F). Interestingly, both months peak at 29°C (84°F to 85°F), but September is notably rainier, with 160 mm (6.3 in) of precipitation over 20 days, compared to June's 63 mm (2.5 in) over 15 days. Additionally, humidity levels are quite similar, with September at 79% and June at 77%. For more detailed insights, check out Culebra weather in June.

In comparing the weather between September and July, we see that both months experience relatively warm temperatures, with September having a slightly higher average temperature of 28°C (82°F) compared to July's 27°C (82°F). The maximum temperatures remain similar, with both months peaking at around 29°C (84°F-85°F). However, September is notably wetter, receiving 160 mm (6.3 in) of precipitation over 20 days, compared to July's 102 mm (4.0 in) over 19 days. Humidity levels are also comparable, with September at 79% and July at 80%. For more details on the specifics of July weather, you can check Culebra weather in July.

In comparing the weather between September and August, we see that both months maintain a similar temperature range, with minimum temperatures around 25°C (78°F) and average highs reaching 29°C (85°F). However, September experiences more precipitation, with a total of 160 mm (6.3 in) over 20 days, compared to August's 114 mm (4.5 in) over 19 days. Humidity levels are slightly lower in August at 80% compared to 79% in September, suggesting a marginally more comfortable atmosphere during the latter month. For a more detailed look at August's weather, you can check Culebra weather in August.

In September, the weather features a warm minimum temperature of 25°C (78°F) and an average temperature of 28°C (82°F), with a maximum reaching 29°C (85°F). The month is marked by significant rainfall, accumulating 160 mm (6.3 in) over 20 days, accompanied by relatively high humidity levels at 79%.

In contrast, October presents slightly cooler averages, with the minimum remaining at 25°C (77°F) and an average of 27°C (82°F), while still peaking at 29°C (85°F). Precipitation decreases to 136 mm (5.4 in) over 18 days, and humidity drops slightly to 78%. Overall, October offers a slightly drier and less humid experience compared to September. For more details, you can check the Culebra weather in October.

In September, the weather is generally warmer, with average temperatures reaching 28°C (82°F) and maximums peaking at 29°C (85°F). However, this month also experiences significant rainfall, totaling 160 mm (6.3 in) over approximately 20 days, coupled with high humidity at 79%. In contrast, November brings slightly cooler temperatures, with an average of 27°C (81°F) and maximums around 28°C (84°F). Precipitation decreases notably to 107 mm (4.2 in) across 17 days, while humidity remains similar at 78%. For a more detailed look at the climate, check out Culebra weather in November.

In September, the weather tends to be warmer and wetter, with average temperatures around 28°C (82°F) and about 160 mm (6.3 in) of precipitation spread over 20 days, resulting in a high humidity level of 79%. In contrast, December experiences slightly cooler conditions, with average temperatures dropping to 26°C (79°F) and significantly less precipitation at 51 mm (2.0 in) over just 15 days, leading to a humidity level of 76%. This shift results in a more comfortable and drier climate in December. For more detailed information, you can check Culebra weather in December.

Compare Culebra's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Culebra

September in Culebra brings a unique blend of warmth and moisture, setting it apart from other months. With average temperatures hovering around a comfortable 28°C, the island remains inviting for visitors. However, this month is characterized by heightened humidity levels, which can make the air feel warmer than it is. Additionally, rainfall becomes more frequent, with about 20 days experiencing precipitation, translating to approximately 160 mm of rain. As such, travelers should be prepared for the occasional shower while enjoying the lush landscapes nurtured by the increased moisture. For a deeper insight into the climatic patterns that influence Culebra throughout the year, check out Culebra Climate.