September Weather in Mayagueez, Puerto Rico

Last updated: August 31, 2025

In Mayagueez, Puerto Rico, September reveals a tropical tapestry of weather characterized by a maximum temperature of 31°C (87°F) and a comfortable average of 28°C (82°F). Nights warm with a minimum of 25°C (78°F) create a pleasant evening atmosphere. However, moisture prevails, with humidity levels at 79%, giving the air a sultry edge. Rain is a frequent visitor this month, accumulating an average of 141 mm (5.5 in) over 18 days, providing lush greenery but often impacting outdoor plans. Embrace the dynamic weather of September, where the island's vibrant beauty thrives amidst the tropical showers.

September Temperature in Mayagueez

In September, the coastal town of Mayagueez, Puerto Rico continues to bask in the warm tropical climate, with temperatures averaging around 28°C (82°F). During this month, you can expect a minimum of 25°C (78°F) and a maximum of 31°C (87°F), maintaining the trend of mild, comfortable heat that defines the region from summer into fall. As the summer months transition into autumn, these temperatures reflect only a slight dip from the peak warmth of August while retaining high humidity and that inviting Caribbean vibe. Overall, September remains an ideal time for beachgoers and outdoor enthusiasts to enjoy the sun before the cooler months usher in.

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

The chart illustrates September temperature patterns in Mayagueez, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Mayagueez, 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).
JanFebMarAprMayJunJulAugSepOctNovDec777777788081828282818079
Data source: Temperature data for Mayagueez 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 Mayagueez

In September, Mayaguez, Puerto Rico experiences a significant surge in precipitation, with a remarkable 141 mm (5.5 in) of rain falling over 18 days. This makes it the wettest month of the year, showcasing a dramatic increase compared to the preceding months. The rainfall in September is nearly double that of August, which recorded 64 mm (2.5 in), indicating a transition into the peak of the wet season. This trend of intensifying rainfall continues from the summer months, where July and August each deliver substantial totals accompanied by 15 rainy days. As the island prepares for the cooler October, September serves as a vivid reminder of the region's dynamic climate, characterized by its robust precipitation patterns.

September Precipitation Trends in Mayagueez

The chart displays monthly precipitation patterns in Mayagueez, 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 Mayagueez, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec1721383949486964141716620
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Mayagueez

In Mayagueez, Puerto Rico, September brings a humidity level of 79%, reflecting the typical tropical climate that characterizes the region. Throughout the year, humidity tends to peak during the summer months, notably in July and August, when it reaches a high of 80%. As the seasons shift, a slight decline can be seen in October and November, with levels dropping to 78%. Interestingly, while January and February register the lowest humidity at 76% and 75% respectively, the relative stability in moisture levels—hovering between 74% and 80%—indicates the island's consistently warm and humid atmosphere, inviting visitors to embrace its vibrant coastal appeal year-round.

September Average Humidity in Mayagueez

This chart illustrates the average monthly humidity levels in Mayagueez, 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 Mayagueez 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 Mayagueez

In Mayagueez, Puerto Rico, September sees a consistently high UV Index of 13, falling into the extreme exposure category, which means it's crucial to take sun safety seriously. The trend from May to September showcases a peak in UV levels, with values hitting 14 in May before slightly stabilizing at 13 through the summer months. This pattern indicates that sun protection is essential, particularly as burn times linger at a swift 10 minutes during this period. As the year shifts, the UV Index begins to decline, dropping to 12 in October and continuing downwards into the winter months. For more detailed information, check the Mayagueez UV Index.

Maximum UV Index Levels in Mayagueez for September

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

As September unfolds in Mayagueez, Puerto Rico, the sun continues to grace the region with a noteworthy 316 hours of shining brilliance. This marks a gentle decline from the peak of 361 hours in both May and July, yet it remains well above the early months of the year like January, which only offers 261 hours. The summer months showcase a vibrant surge in sunshine, peaking in mid-year before gradually tapering off into autumn. However, September still enjoys a generous amount of sunlight, promising warmth and vibrancy as the island transitions into the cooler months. With an average close to 300 hours through the fall, Mayagueez ensures that even as the year draws to a close, the spirit of summer lingers long into the autumn days.

Monthly Sunshine Duration in Mayagueez: September Highlighted

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

Chance of Sun in Mayagueez During September

In Mayaguez, Puerto Rico, the likelihood of sunny weather in September stands at 57%, suggesting a reasonably bright month as summer transitions into fall. Observing the broader trends, September’s sun chances align closely with the percentages seen in January, May, and October, showcasing that while summer’s peak has passed, it still offers a healthy dose of sunshine. Notably, the chance of sun dips in the summer months, reaching its lowest in June at 33%. As the year progresses towards the latter months, there’s a noticeable increase in sunny days, peaking again in the winter months. This pattern highlights September as a sweet spot for enjoying warm, sun-filled days in Mayaguez, perfect for outdoor activities before the rainy season fully sets in.

Percentage of Sunny Days in September in Mayagueez

The chart illustrates the percentage of sunny days in Mayagueez 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 Mayagueez experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec58%80%71%52%58%33%50%49%57%54%65%73%
Data source: Mayagueez September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Mayagueez in September

As the summer months approach, Mayagueez, Puerto Rico enjoys a gradual increase in daylight duration, peaking in June and July with an impressive 13 hours of sunlight each day. This vibrant burst of daylight is a precursor to the gradual tapering that occurs as the year progresses, with September maintaining a comfortable 12 hours of daylight. This steady length of daylight continues to provide ample time for outdoor activities, before transitioning back to shorter days in the autumn months of October and November. Overall, the daylight trends reflect a warm and inviting climate ideal for enjoying the natural beauty of the region throughout the year.

Average Daylight Hours in Mayagueez for September

The chart illustrates the variation in daylight duration in Mayagueez 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: Mayagueez daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Mayagueez

In Mayagueez, Puerto Rico, the September winds usher in a mild transition as summer wanes. With an average wind speed of 3.4 m/s (8 mph), September marks the lowest point in the year, following a gradual decline from the earlier months of June and July, which boast breezes of nearly 4.1 m/s (9 mph). This gentle September airflow sets a serene backdrop for outdoor activities, transitioning smoothly into the slightly brisker October winds at 3.7 m/s (8 mph). Compared to the lively gusts of the preceding months, September’s refreshing calm signifies a moment of respite before the winds pick up again during late fall, inviting both locals and visitors to enjoy the tranquil atmosphere of this beautiful coastal town.

Average September Wind Speed in Mayagueez

The chart displays monthly wind speed patterns in Mayagueez, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.34.84.53.63.54.04.14.03.4 m/s3.73.94.7
Data source: Mayagueez September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Mayagueez Compares to Other Months

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

September and January in Mayaguez exhibit distinct weather patterns that highlight the transition from the wet season to the dry season. In September, temperatures range from a minimum of 25°C (78°F) to a maximum of 31°C (87°F), with an average of 28°C (82°F). This month is also characterized by significant rainfall, totaling 141 mm (5.5 in) over 18 days, and a humidity level of 79%. In contrast, January sees milder temperatures, with a minimum of 23°C (73°F) and a maximum of 28°C (84°F), resulting in an average temperature of 25°C (78°F). Precipitation is markedly lower in January, with only 16 mm (0.6 in) falling over just 4 days, and humidity decreases slightly to 76%. These differences make January a drier and cooler time compared to the warm and wet atmosphere of September. For more detailed information on January weather in Mayaguez, please refer to Mayagueez weather in January.

When comparing the weather in September and February, September tends to be warmer and wetter. In September, temperatures range from a minimum of 25°C (78°F) to a maximum of 31°C (87°F), with an average temperature of 28°C (82°F). The month also sees significant rainfall, totaling 141 mm (5.5 in) across 18 days, and a humidity level of 79%. Conversely, February experiences milder conditions, with temperatures ranging from a minimum of 22°C (72°F) to a maximum of 28°C (83°F), averaging 25°C (77°F). Precipitation in February is notably less, at 21 mm (0.8 in) over just 7 days, and the humidity is slightly lower at 75%. For a more in-depth look at February weather, check out Mayagueez weather in February.

In comparing the weather between September and March, we can see some significant differences. September tends to be warmer, with temperatures ranging from a minimum of 25°C (78°F) to a maximum of 31°C (87°F) and an average of 28°C (82°F). In contrast, March is slightly cooler, with temperatures ranging from 22°C (73°F) to 28°C (83°F) and an average of 25°C (77°F). Precipitation is significantly higher in September, totaling 141 mm (5.5 in) over 18 days, compared to March, which experiences only 38 mm (1.5 in) over 11 days. Additionally, September has a higher humidity level at 79%, while March is a bit less humid at 74%. For more detailed information, you can check Mayagueez weather in March.

In comparing the weather between September and April, September tends to be warmer and wetter. With average temperatures reaching up to 28°C (82°F) and maximums around 31°C (87°F), September experiences higher temperatures than April, where the averages peak at 26°C (78°F) and maximums reach 29°C (84°F). Additionally, September sees significantly more rainfall, with 141 mm (5.5 in) over 18 days, compared to April's 39 mm (1.5 in) across just 12 days. The humidity levels are also slightly higher in September at 79%, while April has a humidity of 75%. For a more detailed look at April's weather, you can check Mayagueez weather in April.

September and May both exhibit warm temperatures, but September tends to be slightly hotter, with average highs reaching 31°C (87°F) compared to May's max of 29°C (85°F). The minimum temperatures are relatively similar, with September at 25°C (78°F) and May slightly lower at 24°C (75°F). However, September experiences significantly more rainfall, with 141 mm (5.5 in) spread over 18 days, whereas May sees only 49 mm (1.9 in) across 14 days. Humidity levels in September are also higher at 79%, compared to 75% in May. For more detailed weather comparisons, you can check Mayagueez weather in May.

September typically sees slightly warmer temperatures compared to June, with average highs reaching 31°C (87°F) versus June's max of 30°C (87°F). However, September experiences significantly more rainfall, totaling 141 mm (5.5 in) over 18 days, compared to June's 48 mm (1.9 in) across just 14 days. Humidity levels are also similar, with September at 79% and June at 77%. Overall, while both months are warm and humid, September tends to be wetter and marginally hotter. For more information about June weather, visit Mayagueez weather in June.

When comparing the weather in September and July, both months experience similar temperature ranges, with minimum temperatures around 25°C (78°F), average temperatures at 28°C (82°F), and maximum temperatures slightly differing at 31°C (87°F) for September and 31°C (88°F) for July. However, September is significantly wetter, recording 141 mm (5.5 in) of precipitation over 18 days, compared to July's 69 mm (2.7 in) across 15 days. Humidity levels remain fairly consistent, with September at 79% and July slightly higher at 80%. For more detailed insights on July weather, visit Mayagueez weather in July.

In August, the weather in Mayaguez features similar temperatures to September, with a minimum of 25°C (77°F) and an average of 28°C (82°F). However, August can reach a slightly higher maximum of 31°C (88°F). The month sees less rainfall, accumulating only 64 mm (2.5 in) over 15 days, compared to September's significantly wetter conditions, which experience 141 mm (5.5 in) of precipitation across 18 days, contributing to a slightly lower humidity of 79% in September compared to 80% in August. For more details on August’s conditions, check out Mayagueez weather in August.

In comparing the weather of September and October, both months showcase similar temperatures, with September averaging 28°C (82°F) and October slightly cooler at 27°C (81°F). The minimum temperatures remain constant at around 25°C (77°F), while the maximum temperatures show a slight increase in October, reaching 31°C (88°F). However, a notable difference lies in the precipitation levels; September experiences significantly more rainfall at 141 mm (5.5 in) over 18 days, while October sees a decrease to 71 mm (2.8 in) across 14 days. Humidity levels also remain comparable, with September at 79% and October slightly lower at 78%. For more details about the weather in October, you can check Mayagueez weather in October.

In September, the weather is typically hot and humid, with temperatures ranging from a minimum of 25°C (78°F) to a maximum of 31°C (87°F), averaging around 28°C (82°F). This month also sees significant rainfall, with 141 mm (5.5 in) of precipitation spread across 18 days and humidity levels at 79%.

By November, temperatures slightly decrease, with a minimum of 24°C (76°F), an average of 27°C (80°F), and a maximum of 30°C (86°F). The precipitation also drops considerably to 66 mm (2.6 in) over 13 days, and humidity remains similar at 78%. Overall, November offers slightly cooler and drier conditions compared to the more intense weather of September. For more details, you can check out Mayagueez weather in November.

In comparing the weather between September and December, September tends to be warmer and wetter. The average temperature in September is 28°C (82°F) with highs reaching up to 31°C (87°F), whereas December brings milder temperatures averaging 26°C (79°F) and a maximum of 29°C (84°F). Additionally, September experiences significantly more rainfall, with 141 mm (5.5 in) over 18 days, while December sees a mere 19 mm (0.8 in) across just 4 days. Humidity levels are also slightly higher in September at 79% compared to December's 76%. For more detailed information on December weather, you can visit Mayagueez weather in December.

Compare Mayagueez's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Mayagueez

As summer fades, September in Mayaguez ushers in a shift in weather, marked by a blend of warmth and moisture. With average temperatures hovering around 28°C (82°F) and a noticeable increase in humidity, visitors can expect a tropical embrace. This month also brings more frequent rainfall, with about 18 days of precipitation contributing to a total of 141 mm (5.5 in). While the temperature remains comfortable, the higher humidity and rainfall differentiate September from the drier, sunnier months that precede and follow it, making it a time when the lush landscapes of Mayaguez truly flourish. To explore the year's climatic trends further, check out Mayagueez Climate.