September Weather in Humacao, Puerto Rico

Last updated: October 30, 2025

In September, Humacao, Puerto Rico experiences a warm and humid climate, with maximum temperatures reaching up to 31°C (88°F) and an average of 27°C (82°F). The month is characterized by significant rainfall, accumulating 195 mm (7.7 in) over 28 days, resulting in a humidity level of 79% that can make the air feel particularly sultry. Visitors can expect a lush tropical ambiance, perfect for enjoying the region's natural beauty, though it's wise to prepare for frequent showers throughout the day.

September Temperature in Humacao

In September, Humacao, Puerto Rico, experiences a warm embrace as temperatures peak, reflecting the vibrant essence of late summer. With minimums hovering around 24°C (76°F) and maximums climbing to a sizzling 31°C (88°F), this month marks one of the hottest periods of the year. The average temperature settles comfortably at 27°C (82°F), providing a perfect canvas for beach days and outdoor adventures. As the island transitions into autumn, the warmth remains consistently inviting, encouraging visitors to explore its lush landscapes and crystalline waters. Overall, September in Humacao is characterized by its tropical allure, where the summer heat lingers joyfully just a bit longer.

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

The chart illustrates September temperature patterns in Humacao, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Humacao, September typically has an average temperature of 27°C (82°F), with highs reaching up to 31°C (88°F) and lows dropping to around 24°C (76°F).
JanFebMarAprMayJunJulAugSepOctNovDec767676777980818181817978
Data source: Temperature data for Humacao 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 Humacao

In September, Humacao, Puerto Rico experiences a notable surge in precipitation, receiving an impressive 195 mm (7.7 inches) of rain over 28 days—the highest monthly total of the year. This increase marks a significant peak following the gradual rise in rainfall from the early months, with the volume nearly doubling from April’s totals. The combination of abundant rainfall and high precipitation days suggests that September represents a transitional period, leading into the wetter months ahead. This consistent moisture not only contributes to the lush tropical landscape but also highlights the region's vulnerability to the potential impacts of storms during the hurricane season.

September Precipitation Trends in Humacao

The chart displays monthly precipitation patterns in Humacao, 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 Humacao, September typically receives around 195 mm (7.7 inches) of precipitation spread over approximately 28 days.
JanFebMarAprMayJunJulAugSepOctNovDec5761787910911014915319618713281
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Humacao

In September, Humacao, Puerto Rico, experiences a humidity level of 79%, reflecting a slight dip from the peak months of July and August, both at 80%. This slight decrease signals the transition toward the drier fall months, as humidity generally trends downward into the latter part of the year. Overall, the data reveals a pattern of relatively high humidity throughout the summer, peaking mid-year before gradually tapering off, culminating in a more comfortable range between 76% and 78% from October through December. The persistence of elevated humidity from June to September illustrates Humacao’s tropical climate, offering a lush and vibrant environment that residents and visitors alike cherish.

September Average Humidity in Humacao

This chart illustrates the average monthly humidity levels in Humacao, 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 Humacao is approximately 79%, 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 Humacao

In September, Humacao, Puerto Rico, experiences a notably high UV Index of 14, placing it in the extreme exposure category with a burn time of only 10 minutes. This trend of escalating UV levels is evident as we move from the beginning of the year until September, with values consistently hitting extremes from February through August, peaking in September. The intensity of the sun's rays during this month underscores the importance of sun protection, especially as early fall brings no respite from the summer’s intense sun. Visitors and residents alike should remain vigilant against UV exposure. For more detailed information, check out the Humacao UV Index.

Maximum UV Index Levels in Humacao for September

The chart shows the monthly maximum UV Index (UVI) for Humacao 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 Humacao typically reaches 14, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec911131313131213141298
Data source: Humacao 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 Humacao

In September, Humacao, Puerto Rico enjoys a delightful average of 318 sunshine hours, continuing the trend of abundant sunlight that peaks in the warmer months. Following the vibrant summer, where July and May boast 354 and 357 hours of sun respectively, September offers a perfect balance as it transitions into the fall season. This month stands as a charming bridge, maintaining a generous amount of sunlight while signaling the gradual shift in weather, with sunshine hours slightly dipping from the summer highs but still outshining the earlier months of the year. As the days begin to shorten, the warmth of the sun continues to cast its glow, inviting residents and visitors alike to revel in the beautiful landscapes and relaxing beaches that Humacao has to offer.

Monthly Sunshine Duration in Humacao: September Highlighted

The September sunshine duration represents the total number of hours Humacao 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.
JanFebMarAprMayJunJulAugSepOctNovDec258h302h348h348h357h344h354h349h318h316h302h320h
Data source: Humacao September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Humacao During September

As summer transitions into fall, September in Humacao, Puerto Rico, presents a mixed bag when it comes to sunshine. With a 46% chance of sunny weather, this month reflects a slight dip in brightness compared to the summer months of July and August. The likelihood of sun is similar to that of October, hinting at a stable yet somewhat unpredictable weather pattern. Interestingly, the sunniest months occur earlier in the year, with February and November boasting a higher chance of clear skies. Overall, while September may not guarantee abundant sunshine, it still offers opportunities for pleasant weather amidst the tropical charm of Puerto Rico.

Percentage of Sunny Days in September in Humacao

The chart illustrates the percentage of sunny days in Humacao 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 Humacao experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec50%65%61%44%51%20%40%37%46%46%57%59%
Data source: Humacao September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Humacao in September

In September, Humacao, Puerto Rico enjoys 12 hours of daylight, maintaining the longer days characteristic of the summer months. As the year progresses from January’s modest 11 hours through the extended light of June and July, daylight begins to subtly decline as autumn approaches. While September holds steady at 12 hours, the gradual transitions throughout the year reveal a gentle rhythm, with longer daylight spilling from the vibrant summer into the early days of fall, before tapering off into the shorter daylight of the coming months. This seamless shift highlights the island’s tropical climate, where sunlight lingers a bit longer, allowing residents to savor the warm, sun-kissed days before the daylight dwindles into winter.

Average Daylight Hours in Humacao for September

The chart illustrates the variation in daylight duration in Humacao 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 12m13h 5m12h 42m12h 12m11h 41m11h 15m11h 2m
Data source: Humacao daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Humacao

In September, the winds in Humacao, Puerto Rico, tend to be gentler compared to the peak summer months, with an average speed of only 3.2 m/s (7 mph). This marks a noticeable decrease from the 5.0 m/s (11 mph) recorded in both July and August, indicating a shift towards calmer conditions. As summer transitions into fall, the variability in wind speed suggests that September serves as a lull, with breezes becoming more subtle before picking up again in the following months. Interestingly, this lower wind speed not only enhances the serene atmosphere of the coastal landscape but also provides a calm backdrop for those enjoying the beautiful Puerto Rican scenery, making it an ideal time for relaxation.

Average September Wind Speed in Humacao

The chart displays monthly wind speed patterns in Humacao, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.05.04.43.74.24.75.04.43.2 m/s3.43.64.4
Data source: Humacao September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Humacao Compares to Other Months

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

In comparing the weather of September and January, September exhibits warmer temperatures with a minimum of 24°C (76°F), averaging 27°C (82°F), and peaking at 31°C (88°F). This month is also characterized by significant rainfall, totaling 195 mm (7.7 in) over 28 days, along with high humidity at 79%. In contrast, January is slightly cooler, with temperatures ranging from a minimum of 21°C (70°F) to an average of 25°C (77°F), and a maximum of 28°C (83°F). Precipitation in January is considerably lower at 57 mm (2.3 in) spread across 17 days, with humidity at 76%. For more detailed insights into January weather, visit Humacao weather in January.

September typically experiences warmer weather compared to February, with average temperatures reaching around 27°C (82°F) and occasional highs of 31°C (88°F). In contrast, February enjoys milder conditions, where the average temperature is about 24°C (76°F) and peaks at 27°C (81°F). Additionally, September sees significantly more precipitation, with 195 mm (7.7 in) falling over 28 days, while February only receives 61 mm (2.4 in) across 21 days. Both months exhibit high humidity levels, with September at 79% and February slightly lower at 75%. For more detailed information, you can check out Humacao weather in February.

When comparing the weather in September and March, September tends to be warmer and wetter. In September, the temperature ranges from a minimum of 24°C (76°F) to a maximum of 31°C (88°F), with an average of 27°C (82°F). The month also experiences significant rainfall, with 195 mm (7.7 in) of precipitation over 28 days, contributing to a high humidity level of 79%. On the other hand, March is slightly cooler, with temperatures ranging from 22°C (72°F) to 28°C (82°F) and an average of 25°C (76°F). It sees much less rainfall, with only 78 mm (3.1 in) over 22 days and a humidity level of 74%. For more detailed information on the weather in March, visit Humacao weather in March.

When comparing the weather in September and April, September tends to be warmer and wetter. In September, the average temperature reaches around 27°C (82°F), with highs of 31°C (88°F) and a notable humidity of 79%. This month also experiences significant rainfall, averaging 195 mm (7.7 in) over 28 days. In contrast, April is slightly cooler, with an average temperature of 25°C (77°F) and maximums of 29°C (84°F). Rainfall in April is considerably less, at about 79 mm (3.1 in) spread over just 20 days, accompanied by slightly lower humidity at 75%. For a more detailed look at the weather patterns in April, you can check Humacao weather in April.

In comparing the weather of September and May, we can observe that September tends to be warmer, with temperatures ranging from a minimum of 24°C (76°F) to a maximum of 31°C (88°F), resulting in an average temperature of 27°C (82°F). In contrast, May experiences slightly cooler temperatures, with a range from 23°C (73°F) to 29°C (85°F) and an average of 26°C (79°F). Additionally, September is notably wetter, receiving 195 mm (7.7 in) of precipitation over 28 days, while May has just 109 mm (4.3 in) of rain over 26 days. Humidity levels are also higher in September at 79%, compared to May's 75%. For more detailed insights, you can check out Humacao weather in May.

In comparing the weather of September to that of June, we see that both months maintain similar temperature ranges, with September experiencing average temperatures around 27°C (82°F) and June hovering at 27°C (80°F). However, September tends to be a bit wetter, receiving approximately 195 mm (7.7 in) of rainfall over 28 days, compared to June’s 110 mm (4.3 in) across 26 days. The humidity remains high in both months, with September at 79% and June slightly lower at 77%. If you're curious about the specifics of June weather, you can check Humacao weather in June.

In comparing the weather between September and July, both months exhibit warm temperatures, with minimums hovering around 24°C (75-24°F) and average highs reaching around 30-31°C (86-88°F). September sees slightly higher maximum temperatures, averaging 31°C (88°F), compared to July's max of 30°C (86°F). Rainfall is notably more intense in September, with 195 mm (7.7 in) falling over the course of 28 days, while July has a total precipitation of 149 mm (5.9 in) spread over 27 days. Despite the rainfall, humidity remains fairly consistent, with September at 79% and July at 80%. For a detailed look at July's weather, you can visit Humacao weather in July.

In comparing the weather of September to August, both months exhibit similar average temperatures, with September slightly warmer at a maximum of 31°C (88°F) compared to August's 30°C (87°F). However, September is considerably wetter, receiving 195 mm (7.7 in) of precipitation over 28 days, in contrast to August's 153 mm (6.0 in) over 27 days. Humidity levels remain relatively close, with September at 79% and August at 80%. For more detailed weather information, you can check out Humacao weather in August.

In September, the weather features warm temperatures with a minimum of 24°C (76°F), an average of 27°C (82°F), and a maximum of 31°C (88°F). The month sees significant rainfall, totaling 195 mm (7.7 in) over 28 days, contributing to a high humidity level of 79%. In contrast, October maintains similar temperatures, with a minimum of 24°C (75°F), an average of 27°C (81°F), and a slightly lower maximum of 30°C (87°F). Rainfall in October also decreases slightly to 187 mm (7.4 in) over 26 days, with humidity dropping marginally to 78%. For more details on the specific conditions, visit Humacao weather in October.

September and November both feature warm temperatures, but there are noticeable differences in weather patterns. In September, the minimum temperature averages around 24°C (76°F) and can reach up to 31°C (88°F), with an overall average of 27°C (82°F). This month experiences significant rainfall, with a total of 195 mm (7.7 in) measured over 28 days, leading to a higher humidity level of 79%.

In contrast, November sees slightly cooler temperatures, with a minimum of 23°C (74°F) and a maximum of 29°C (85°F), averaging at 26°C (80°F). Precipitation drops to 131 mm (5.2 in) over 25 days, resulting in a marginally lower humidity of 78%. For more detailed information about the weather in November, you can check Humacao weather in November.

In September, the weather tends to be warmer and more humid, with average temperatures reaching around 27°C (82°F) and maximums peaking at 31°C (88°F). This month also experiences considerable rainfall, with precipitation totaling 195 mm (7.7 in) over 28 days, leading to a humidity level of 79%. In contrast, December sees slightly cooler conditions, with average temperatures dropping to 26°C (78°F) and maximums averaging 29°C (85°F). The month is drier, with only 81 mm (3.2 in) of precipitation over 24 days and a humidity level of 76%. For more detailed information, you can check Humacao weather in December.

Compare Humacao's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Humacao

As September unfolds in Humacao, the weather undergoes a notable shift compared to the rest of the year. With warm temperatures averaging around 27°C (82°F) and high humidity levels at 79%, the month is characterized by a rich tropical atmosphere. Frequent rainfall, often pouring nearly every day, contributes to a significant 195 mm of precipitation, making it one of the wettest months on record. This consistent moisture not only enhances the vibrant local flora but also sets a unique tone for outdoor activities. If you're looking to plan your visit, be sure to check out the complete details about the weather patterns on our page: Humacao Climate.