September Weather in Guanica, Puerto Rico

Last updated: August 31, 2025

In Guanica, Puerto Rico, September ushers in warm temperatures with a maximum reaching 32°C (90°F) and maintaining an average of 27°C (81°F), while nights are comfortably mild at a minimum of 24°C (76°F). This month is characterized by a significant amount of precipitation, totaling 159 mm (6.2 in) over approximately 21 days, contributing to the region's lush landscape. The humidity levels hover around 79%, creating a tropical atmosphere that can be both refreshing and humid. Visitors and locals alike can expect a blend of sun and rain, making it essential to enjoy the vibrant natural beauty while preparing for sudden showers.

September Temperature in Guanica

In September, Guanica, Puerto Rico, sees warm and inviting temperatures that are characteristic of its tropical climate. The minimum temperature settles at a comfortable 24°C (76°F), while the average hovers around 27°C (81°F), reaching a sultry maximum of 32°C (90°F). As summer transitions into fall, the heat remains consistent, with only a slight uptick from August, suggesting an enduring warmth throughout the month. This pattern emphasizes Guanica's subtropical allure, making it an ideal spot for those seeking sun-soaked days and balmy nights. The steadiness in temperature invites visitors to enjoy the beautiful coastal scenery, whether lounging on the beach or exploring the vibrant local culture.

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

The chart illustrates September temperature patterns in Guanica, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Guanica, 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).
JanFebMarAprMayJunJulAugSepOctNovDec767676777980818181807978
Data source: Temperature data for Guanica generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Guanica

In September, Guanica experiences a significant surge in precipitation, with 159 mm (6.2 in) of rainfall over 21 days, marking it as the wettest month of the year. This increase in rainfall is notable compared to August, which saw 96 mm (3.8 in) across 16 days. As the dry season approaches, this monthly deluge can be attributed to seasonal weather patterns, providing a vital water source for the region. Interestingly, the trend reveals a gradual rise from earlier months, where May and June recorded much lighter amounts of 59 mm (2.3 in) and 53 mm (2.1 in), respectively. This rainy crescendo in September prepares the landscape for the drier months ahead, reflecting the dynamic climate of this beautiful coastal town.

September Precipitation Trends in Guanica

The chart displays monthly precipitation patterns in Guanica, 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 Guanica, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec19264949595386961591029125
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Guanica

In Guanica, Puerto Rico, September brings a moderate humidity level of 79%, which reflects a slight decrease from the peak experienced during the summer months. As the year progresses, the humidity tends to rise gradually, peaking in July at 81% before tapering off in the colder months. While September's humidity is notable, it marks a transition from the higher levels of August, which saw 80% humidity. This trend suggests that as summer gives way to fall, residents and visitors can expect a more comfortable atmosphere, yet still humid enough to remind them of the tropical climate that characterizes this beautiful region year-round.

September Average Humidity in Guanica

This chart illustrates the average monthly humidity levels in Guanica, 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 Guanica is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%75%75%76%76%78%81%80%79%79%78%77%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Guanica

In September, Guanica, Puerto Rico experiences a consistently high UV Index of 13, placing it in the extreme exposure category with a quick burn time of just 10 minutes. This trend of elevated UV levels continues from the previous summer months, indicating that the intense sun exposure does not wane as the season shifts. With the UV Index remaining steady throughout the latter part of summer and into early fall, it’s crucial for residents and visitors alike to prioritize sun protection during this time. To learn more about the UV Index patterns throughout the year, visit Guanica UV Index.

Maximum UV Index Levels in Guanica for September

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

September in Guanica, Puerto Rico, brings a delightful blend of sunshine with 318 hours of bright rays, offering a radiant end to summer. As the month transitions from August's 353 hours, there’s a noticeable dip, but the warmth and light continue to grace the region significantly. This period marks a shift, as the summer months boast the highest sunshine levels, peaking in May with an impressive 363 hours. As the year approaches its latter stages, sunshine hours gradually decline, illustrating the island's vibrant yet changing climate. Despite the reduction in daylight, September remains a vibrant time, ensuring that residents and visitors alike can enjoy the lingering summer vibes under the Puerto Rican sun.

Monthly Sunshine Duration in Guanica: September Highlighted

The September sunshine duration represents the total number of hours Guanica 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.
JanFebMarAprMayJunJulAugSepOctNovDec262h308h348h353h363h352h361h353h318h317h299h320h
Data source: Guanica September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Guanica During September

In September, Guanica, Puerto Rico experiences a 55% chance of sunny weather, making it a relatively favorable month for sun-seekers. This figure demonstrates a slight increase from the summer months of July and August, which see chances of sunshine dip to 49% and 47% respectively. As the year progresses, September's sunny likelihood positions it closely to the early winter months of January and October, both at 54%. Overall, while the likelihood of sunny days fluctuates throughout the year, September stands out as a transitional month where sunshine begins to reclaim its prominence after the peak of the summer rains.

Percentage of Sunny Days in September in Guanica

The chart illustrates the percentage of sunny days in Guanica 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 Guanica experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec54%79%68%49%57%32%49%47%55%54%61%70%
Data source: Guanica September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Guanica in September

In Guanica, Puerto Rico, the daylight duration follows a rhythmic pattern throughout the year. Starting with a consistent 11 hours in both January and February, the days gradually lengthen as spring approaches, peaking at 13 hours during the height of summer in June and July. As the year transitions into fall, daylight begins to taper off, returning to 12 hours in September before dipping once again to 11 hours by October. This trend not only highlights the island's tropical climate but also showcases the gentle shifts in natural light that accompany the changing seasons, creating a captivating environment year-round.

Average Daylight Hours in Guanica for September

The chart illustrates the variation in daylight duration in Guanica throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 10m11h 32m12h 2m12h 33m12h 58m13h 10m13h 4m12h 41m12h 12m11h 42m11h 16m11h 3m
Data source: Guanica daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Guanica

In September, the winds in Guanica, Puerto Rico experience a noticeable dip, with an average speed of just 3.1 m/s (7 mph)—the lowest of the year. This tranquil breeze contrasts sharply with the stronger gusts of the summer months, particularly in July, which boasted an average of 5.1 m/s (12 mph). The transition towards fall brings a gentle calmness, as the winds begin to shift from their summer vigor. September's softer winds set the stage for the upcoming months, where speeds gradually rise again in October. This seasonal ebb and flow highlights the region's dynamic climate, offering a unique blend of leisurely breezes and invigorating gusts throughout the year.

Average September Wind Speed in Guanica

The chart displays monthly wind speed patterns in Guanica, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.95.54.23.94.44.85.14.23.1 m/s4.03.64.2
Data source: Guanica September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Guanica Compares to Other Months

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

In September, the weather is noticeably warmer with average temperatures reaching 27°C (81°F) and highs peaking at 32°C (90°F). This month is also characterized by significant rainfall, with 159 mm (6.2 inches) of precipitation spread over 21 days, resulting in a humid atmosphere with 79% humidity. In contrast, January brings cooler conditions, with average temperatures dropping to 25°C (77°F) and maximums of 29°C (84°F). The rainfall sharply declines to just 18 mm (0.7 inches) occurring only on 4 days, creating a drier environment with slightly lower humidity at 76%. For more details on the weather in January, you can check Guanica weather in January.

In September, the weather is noticeably warmer, with temperatures ranging from a minimum of 24°C (76°F) to a maximum of 32°C (90°F) and an average of 27°C (81°F). This month is also characterized by high humidity at 79% and significant rainfall, accumulating 159 mm (6.2 in) over 21 days. In contrast, February experiences milder conditions, with temperatures ranging from 21°C (70°F) to a maximum of 29°C (85°F), averaging 25°C (77°F). Furthermore, February is much drier, receiving only 26 mm (1.0 in) of precipitation across just 5 days and a slightly lower humidity level of 75%. For more detailed information, check out Guanica weather in February.

When comparing the weather in September and March, several notable differences emerge. September tends to be warmer overall, with average temperatures reaching about 27°C (81°F) and maximums peaking at 32°C (90°F), contrasted with March's milder averages of 24°C (76°F) and maximums of 28°C (83°F). Additionally, September experiences significantly more rainfall, with 159 mm (6.2 in) spread over 21 days, while March sees just 49 mm (1.9 in) of precipitation across only 11 days. The humidity levels are similar, with September at 79% and March slightly lower at 75%. For more details on weather conditions during March, you can explore Guanica weather in March.

When comparing the weather in September and April, several key differences emerge. September typically features warmer temperatures, with an average ranging from a minimum of 24°C (76°F) to a maximum of 32°C (90°F), while April's average temperatures are cooler, peaking at 29°C (84°F). In terms of precipitation, September is notably wetter, receiving 159 mm (6.2 in) over 21 days compared to April's 49 mm (1.9 in) over 14 days. Humidity levels are similar, with September at 79% and April slightly lower at 76%. For more detailed information, you can check Guanica weather in April.

In comparing the weather of September and May, September tends to be warmer, with an average temperature of 27°C (81°F) compared to May's 26°C (79°F). The maximum temperatures in September can reach 32°C (90°F), slightly higher than May's maximum of 30°C (86°F). However, September also experiences significantly more precipitation, with 159 mm (6.2 in) over 21 days, while May only sees 59 mm (2.3 in) across 12 days. The humidity levels are relatively similar, with September at 79% and May at 76%, making both months feel quite warm and tropical. For more specific details, you can check Guanica weather in May.

In comparing the weather of September and June, both months showcase warm temperatures, with September slightly edging out in maximum averages at 32°C (90°F) compared to June's 31°C (88°F). Interestingly, both months feature similar average temperatures, around 27°C (81°F). However, September is distinctly wetter, experiencing a significant increase in rainfall with 159 mm (6.2 in) over 21 days, while June sees just 53 mm (2.1 in) across 12 days. Humidity levels remain comparable, with September at 79% and June at 78%. For more specific details, you can check out Guanica weather in June.

In comparing the weather between September and July, both months display similar temperature ranges, with September having an average temperature of 27°C (81°F) and a maximum of 32°C (90°F), while July's averages align closely with a minimum of 24°C (75°F) and a maximum of 31°C (88°F). However, September is considerably wetter, receiving 159 mm (6.2 in) of rainfall over 21 days compared to July's 86 mm (3.4 in) over 16 days. Additionally, the humidity remains quite high in both months, with September at 79% and July slightly higher at 81%. For more details on July weather, you can visit Guanica weather in July.

In comparing the weather between August and September, both months exhibit similar temperature ranges, with average highs hitting 32°C (90°F) and lows around 24°C (76°F) in September and 23°C (74°F) in August. However, September is characterized by significantly increased precipitation, totaling 159 mm (6.2 in) over 21 days, compared to August's 96 mm (3.8 in) over 16 days. Humidity levels remain fairly constant, with September at 79% and August slightly higher at 80%. For more detailed insights into August weather, you can visit Guanica weather in August.

September and October exhibit similar temperature patterns, with both months having a minimum temperature of around 24°C (75-76°F) and an average temperature of approximately 27°C (80-81°F). However, October tends to be slightly cooler, with a maximum temperature of 31°C (88°F) compared to September's 32°C (90°F). In terms of precipitation, October sees a significant decrease, with 102 mm (4.0 in) over 20 days, whereas September experiences 159 mm (6.2 in) over 21 days, indicating a drier trend as the months progress. Additionally, humidity remains fairly consistent, with October at 78% and September slightly higher at 79%. For more detailed information, check out Guanica weather in October.

In September, temperatures are slightly warmer, with a minimum of 24°C (76°F) and an average high reaching 32°C (90°F). This month is characterized by significant rainfall, totaling 159 mm (6.2 inches) over 21 days, and high humidity levels averaging 79%. In contrast, November sees a slight decrease in temperatures, with minimums of 23°C (73°F) and an average high of 31°C (88°F). Additionally, November experiences much less precipitation, with only 91 mm (3.6 inches) over 15 days and a humidity level of 78%. For more detailed information on November weather, you can check the following link: Guanica weather in November.

In September, temperatures are slightly warmer with a minimum of 24°C (76°F) and an average of 27°C (81°F), reaching a maximum of 32°C (90°F). This month also sees considerable rainfall, with a total of 159 mm (6.2 in) over 21 days and humidity levels around 79%. In contrast, December brings cooler temperatures, with a minimum of 22°C (72°F) and an average of 26°C (78°F), peaking at 30°C (86°F). Rainfall is significantly reduced in December, totaling only 25 mm (1.0 in) across just 7 days and slightly lower humidity at 77%. For more detailed weather insights, you can check out Guanica weather in December.

Compare Guanica's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Guanica

As September rolls in, Guanica experiences a distinct shift in its weather patterns compared to other months. The temperatures remain warm, with averages around 27°C (81°F), fostering a tropical environment ideal for outdoor activities, albeit with a higher level of humidity at 79%. However, it's also a month marked by increased precipitation, as the region sees around 21 rainy days, contributing to a total of 159 mm of rainfall. This makes September feel more humid and wetter than the drier months preceding it, particularly influencing local flora and fauna. For a deeper understanding of how these weather conditions play a role in the overall climate, visit Guanica Climate.