Last updated: August 31, 2025
September in Bayamon, Puerto Rico showcases a blend of warmth and moisture, with temperatures reaching a maximum of 32°C (90°F) and an average of 28°C (82°F), while the minimum hovers around 25°C (77°F). The month is characterized by high humidity, averaging 79%, creating a lush tropical atmosphere. With 172 mm (6.8 in) of precipitation spread over 23 days, rain showers are a frequent visitor, adding to the region's vibrant, green landscapes. Visitors can expect a warm, albeit wet, experience that captures the essence of Puerto Rican climate in September.
In September, Bayamon, Puerto Rico, experiences warm and inviting temperatures, reflective of the tropical climate that characterizes the region. With minimums around 25°C (77°F) and averages peaking at 28°C (82°F), the month maintains a comfortable warmth, perfect for enjoying outdoor activities. The maximum temperature can reach up to 32°C (90°F), ensuring that the summer's heat lingers a bit longer. This trend showcases a slight increase in warmth compared to the earlier months of the year, particularly as Bayamon transitions into autumn. The consistent warmth, paired with September’s humid conditions, makes it an ideal time for both relaxation and adventure in this vibrant coastal city.
In September, Bayamon, Puerto Rico experiences its wettest month of the year, with a dramatic precipitation amount of 172 mm (6.8 in) spread over 23 days. This marks a significant increase from the preceding months, where rainfall steadily climbed from 39 mm in January to 86 mm in August. The intensifying rainfall during September not only highlights a peak in the wet season but also sets the stage for a shift into the drier months that follow. While residents contend with the potential challenges of extended rainy days, this abundant precipitation also fuels the lush greenery and vibrant ecosystems characteristic of the region, showcasing nature's ability to thrive amidst the downpours.
September in Bayamon, Puerto Rico, typically experiences a humidity level of 79%, which reflects a slight decrease from the peak months of July and August, both at 80%. As summer wanes, the humidity begins to ease, hinting at the transition into the cooler months ahead. Overall, the data showcases a relatively stable humidity pattern throughout the year, with January through June hovering around the mid-70s to 77%, then climbing to the summer peak before tapering off again in October and November. This consistent humidity creates a warm, tropical atmosphere, characteristic of Bayamon's inviting climate.
In September, Bayamon, Puerto Rico, maintains its status as a sun-drenched haven with a consistently high UV Index of 13, placing it in the extreme exposure category and resulting in a swift burn time of just 10 minutes. This month follows a remarkable trend observed from May through October, where the UV Index remains stubbornly high, with values from 13 to 14, requiring residents and visitors to take necessary precautions against sun exposure. This pattern serves as a reminder of the importance of sun safety in Bayamon, especially as summer transitions into fall. For more details on UV levels and how to protect yourself, check out the Bayamon UV Index.
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In Bayamon, Puerto Rico, September enjoys a delightful 311 hours of sunshine, marking a slight dip from the sun-soaked peak of 356 hours in May. This month transitions from the vibrant summer energy, where July and August bask in over 350 hours of sunlight, into the mellow tones of autumn. With a consistent trend of abundant sunshine throughout the year—particularly in the spring and summer months—September offers a perfect blend of warm days and refreshing breezes, providing residents and visitors alike a beautiful backdrop for outdoor activities before the cooler months set in. The steady decrease in sunlight towards the year’s end hints at the arrival of cozy, milder days ahead, making this month a lovely time to enjoy the lingering summer spirit.
In September, Bayamón, Puerto Rico, experiences a 48% chance of sunny weather, slightly below the annual average. This month typically marks a transition from the summer's more unpredictable storms to the drying season, but the sun still makes a reliable appearance on almost half the days. Interestingly, as we glance at the trend throughout the year, the likelihood of sunshine generally peaks in the colder months, particularly February with a 71% chance, while the summer months of June and July see the lowest probabilities of clear skies. Despite the fluctuations, September remains a pleasant time to visit, blending a moderate chance of sunshine with the lingering warmth of summer.
In September, Bayamon, Puerto Rico enjoys a delightful 12 hours of daylight, maintaining the steady trend observed since May. As the summer months give way to the softer hues of autumn, daylight gradually begins its subtle decline. Interestingly, the year starts with consistent 11-hour days from January to February, before gradually stretching to a peak of 13 hours in June and July. After this zenith, daylight remains abundant before tapering off again in the fall. The seasonal rhythm of light in Bayamon, characterized by its gradual shifts, beautifully reflects the passage of time on this vibrant island.
In September, Bayamon, Puerto Rico experiences a notable dip in wind speed, averaging just 3.2 m/s (7 mph), making it one of the calmest months of the year. This decline follows a summer of slightly breezier conditions, particularly in July and August, where the winds picked up to about 5.3 m/s (12 mph) and 4.7 m/s (11 mph) respectively. As September ushers in the start of the fall season, residents and visitors alike enjoy a serene atmosphere, which is in stark contrast to the more energetic breezes experienced earlier in the year. With wind speeds generally fluctuating between 3.8 m/s and 5.3 m/s in the months leading up to September, the gentle winds in this month mark a seasonal shift, setting the stage for the more tranquil conditions that accompany the onset of autumn in this vibrant coastal town.
Weather in Bayamon varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Bayamon, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January showcase distinct weather patterns. In September, temperatures are warmer with a minimum of 25°C (77°F) and an average of 28°C (82°F), reaching a maximum of 32°C (90°F). The month is also marked by significant rainfall, receiving 172 mm (6.8 in) over approximately 23 days, contributing to higher humidity levels of 79%. In contrast, January brings cooler conditions, with temperatures ranging from a minimum of 20°C (69°F) to an average of 25°C (77°F) and a maximum of 30°C (86°F). Precipitation decreases dramatically in January to 39 mm (1.5 in) spread over just 12 days, resulting in a slightly lower humidity of 76%. For more detailed information, you can visit Bayamon weather in January.
In September, the weather tends to be warmer and more humid, with average temperatures reaching 28°C (82°F) and highs up to 32°C (90°F). The month also experiences significant rainfall, averaging 172 mm (6.8 in) over about 23 days, contributing to a humidity level of 79%. In contrast, February offers a more temperate climate, with average temperatures around 25°C (77°F) and maximums of 30°C (85°F). Rainfall is considerably lighter during this month, totaling just 43 mm (1.7 in) across 13 days, and humidity decreases slightly to 75%. For more details about February's weather, check out Bayamon weather in February.
In September, the weather is generally warmer and more humid compared to March, with minimum temperatures of 25°C (77°F) and an average of 28°C (82°F), peaking at 32°C (90°F). This month also experiences significant rainfall, with 172 mm (6.8 in) spread over 23 days, leading to a humidity level of 79%. In contrast, March has milder temperatures, with minimums of 21°C (70°F) and an average of 25°C (77°F), reaching a maximum of 31°C (87°F). March sees less precipitation, with only 72 mm (2.8 in) across 14 days and a slightly lower humidity at 74%. To learn more about the weather specifics in March, you can visit Bayamon weather in March.
In comparing the weather between September and April, September tends to be warmer and wetter. The average temperature in September reaches around 28°C (82°F) with highs of 32°C (90°F), while April is slightly cooler with an average of 26°C (78°F) and maximum temperatures of 31°C (88°F). Additionally, September experiences significantly higher rainfall, with 172 mm (6.8 in) of precipitation over about 23 days, compared to April's more modest 55 mm (2.2 in) across just 10 days. Humidity levels are also slightly higher in September at 79%, compared to 75% in April. For a more detailed look at April's weather specifics, you can visit Bayamon weather in April.
When comparing the weather in September and May, we find that September is generally warmer and more humid. In September, the average temperature is around 28°C (82°F), with minimums of 25°C (77°F) and maximums reaching 32°C (90°F). This month also sees significant rainfall, with 172 mm (6.8 in) of precipitation spread over 23 days, leading to a humidity level of 79%. In contrast, May features slightly cooler temperatures, averaging 27°C (80°F), with minimums of 23°C (73°F) and similar maximums of 32°C (90°F). Moreover, May experiences much less rainfall, with only 58 mm (2.3 in) of precipitation over 14 days and a lower humidity of 75%. For a closer look at May's weather specifics, you can check Bayamon weather in May.
In comparing the weather of September and June, both months feature similar maximum temperatures, reaching up to 32°C (90°F). However, September tends to be slightly warmer on average with temperatures around 28°C (82°F), compared to June’s average of 27°C (81°F). One major difference is the level of precipitation; September experiences significantly more rainfall with 172 mm (6.8 in) over 23 days, while June sees only 62 mm (2.4 in) across 15 days. Additionally, the humidity in September remains high at 79%, slightly above June's 77%. For more detailed insights into June's weather patterns, visit Bayamon weather in June.
In comparing the weather of September and July, we see that both months experience similar temperature ranges, with minimums around 24-25°C (76-77°F), averages of 28°C (82°F), and maximums reaching up to 32°C (90°F). However, September is notably wetter, receiving 172 mm (6.8 in) of precipitation over 23 days, compared to July's 76 mm (3.0 in) over 17 days. Humidity levels remain quite comparable, with September at 79% and July slightly higher at 80%. For a detailed look at July's weather in Bayamon, you can visit Bayamon weather in July.
September's weather shows a slight increase in precipitation compared to August, with 172 mm (6.8 in) occurring over 23 days, in contrast to August's 86 mm (3.4 in) over 18 days. Despite both months sharing similar temperature ranges, with a minimum of 25°C (77°F), an average of 28°C (82°F), and a maximum of 32°C (90°F), September is characterized by higher humidity at 79%, compared to August's 80%. For more details about August weather specifically, you can check Bayamon weather in August.
In September, the weather tends to be warmer with an average temperature of 28°C (82°F) and maximums reaching up to 32°C (90°F). This month also sees a higher level of precipitation, totaling 172 mm (6.8 in) over 23 days, accompanied by high humidity at 79%. In contrast, October offers slightly cooler temperatures, with an average of 27°C (81°F) and minimums around 24°C (75°F). Precipitation decreases to 136 mm (5.3 in) over 22 days, and humidity slightly drops to 78%. For more detailed information, you can visit Bayamon weather in October.
September and November display some notable differences in weather patterns. In September, temperatures tend to be higher, with a minimum of 25°C (77°F) and an average of 28°C (82°F), peaking at 32°C (90°F). The month is also characterized by significant rainfall, totaling 172 mm (6.8 in) over 23 days, accompanied by a high humidity level of 79%. In contrast, November sees slightly cooler temperatures, with a minimum of 23°C (74°F) and an average of 26°C (80°F), reaching a maximum of 30°C (87°F). Precipitation is notably reduced to 93 mm (3.7 in) over 17 days, alongside a marginally lower humidity of 78%. For more detailed weather information, visit Bayamon weather in November.
In September, the weather is characterized by warmer temperatures, with minimums around 25°C (77°F) and averages peaking at 28°C (82°F). The month is also quite humid, with humidity levels at 79% and significant rainfall of 172 mm (6.8 in) spread over 23 days. In contrast, December offers a slightly cooler climate, with average temperatures dropping to about 26°C (78°F) and maximums reaching 31°C (87°F). Additionally, December sees much less precipitation, totaling 50 mm (2.0 in) over 16 days, and a slightly lower humidity level of 76%. For more details on the December weather in Bayamon, you can check Bayamon weather in December.
As the summer wanes, September in Bayamon brings a unique blend of warmth and moisture, setting it apart from the drier months of the year. With its average temperatures hovering around a comfortable 28°C, residents and visitors alike can expect sticky and humid days, amplified by nearly three-quarters of the month experiencing rainfall. This contrast makes September one of the wetter months, contributing to lush landscapes but also affecting outdoor plans. If you're curious about how September fits into the larger climate picture, explore more at Bayamon Climate.