Last updated: August 31, 2025
September in Arecibo, Puerto Rico is characterized by warm, tropical conditions, with maximum temperatures reaching up to 32°C (90°F) and an average temperature of 27°C (81°F). Residents and visitors can expect a mild minimum temperature of 24°C (75°F) during the month. While the heat is palpable, September also brings significant humidity, averaging 79%, creating a humid environment typical of the Caribbean. Rainfall is another notable feature, with approximately 205 mm (8.1 in) of precipitation spread across 23 days, making it one of the wetter months in the region. Those planning to experience Arecibo's vibrant scenery should be prepared for both the heat and the frequent showers that define this lush paradise during September.
In September, Arecibo, Puerto Rico, continues to bask in warm tropical warmth, with temperatures hovering comfortably between a minimum of 24°C (75°F) and a maximum of 32°C (90°F). This month maintains the high standards set during the summer, reflecting a consistent average temperature of 27°C (81°F). As the year transitions into autumn, the warmth lingers, mirroring August’s temperatures closely, which hints at the region's gratifying tropical climate. Therefore, September presents an excellent opportunity to enjoy outdoor activities, even as surrounding months begin to show slightly cooler nights, particularly in October. This ongoing warmth not only enriches Arecibo's vibrant culture but also invites travelers to immerse themselves in the breathtaking beauty of its landscapes.
In September, Arecibo, Puerto Rico, experiences a significant uptick in precipitation, with a staggering 205 mm (8.1 in) of rainfall, making it one of the wettest months of the year. This surge in rainfall coincides with an increased number of wet days, totaling 23 throughout the month, underscoring the transition into the peak of the rainy season. Compared to the previous months, September's precipitation is markedly higher, reflecting patterns typical of tropical climates where moisture levels escalate as summer wanes. This trend not only contributes to lush landscapes but also emphasizes the need for preparedness in the face of potential flooding and other weather-related challenges that accompany such abundant rainfall.
In September, Arecibo, Puerto Rico, experiences a humidity level of 79%, reflecting the region's tropical climate as it transitions from the peak summer months. This slight dip from the humid 80% recorded in both July and August suggests a subtle easing in moisture as fall approaches. Throughout the year, humidity in Arecibo tends to hover around the mid-70s to low-80s, with a minimum of 74% in March. Notably, the summer months tend to bring higher humidity, peaking in July and August, while September marks a shift towards slightly drier conditions, aligning with the overall trend of consistent humidity levels. This transition makes September a unique time in Arecibo, as the humid air begins to merge with the cooler breezes of autumn, offering a refreshing respite.
In Arecibo, Puerto Rico, the UV Index remains strikingly high throughout the year, particularly from February to September, where it consistently falls within the extreme category. September holds steady with a UV Index of 13, similar to the preceding months of June, July, and August. This sustained intensity translates to a quick burn time of just 10 minutes, emphasizing the need for effective sun protection. As the year progresses toward October, there is a slight decrease, with the UV Index tapering to 12, yet the continuous prevalence of extreme exposure reminds residents and visitors alike of the importance of sun safety year-round. To learn more about daily UV levels and tips for protection in this tropical paradise, check out Arecibo UV Index.
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As September arrives in Arecibo, Puerto Rico, the sun continues to shine brightly, offering an impressive 314 hours of sunshine. While this marks a slight dip from the peak brightness of summer months, July and May, which basked in 359 hours of golden rays, it still reflects the region's bountiful weather. Notably, the trend throughout the year shows a gradual increase in sunlight from January's 259 hours to May's 359 hours, before stabilizing in the fall. This gentle transition into autumn provides locals and visitors alike with a vibrant backdrop for outdoor adventures, ensuring that Arecibo remains a sunny haven even as the days grow shorter.
September in Arecibo, Puerto Rico, features a 49% chance of sunny weather, marking a transitional period as summer begins to wane. This percentage is fairly average compared to other months, revealing an intriguing trend: the likelihood of sunshine dips slightly during the latter part of summer, with June and July showing the lowest probabilities at 29% and 45%, respectively. As September progresses, the sunshine chances hold steady but are still overshadowed by the sunnier months of February (75%) and November (62%). Although September may not promise abundant sunshine, its moderate climate and inviting warmth make it a charming time to enjoy the island’s beauty, especially for those seeking a balance between sun and shade.
As September rolls in, Arecibo, Puerto Rico, experiences a return to 12 hours of daylight, mirroring the summer months' extended sunshine before gradually shifting toward shorter days. The month stands out as a transitional period, where the days begin to wane slightly from the peak of 13 hours seen in June and July. Interestingly, the daylight duration remains unchanged from August, suggesting a consistent rhythm in the tropical climate. This pattern of shifting light continues into October, where daylight dips back to 11 hours, hinting at the approach of the cooler months while still retaining the warm, vibrant essence that characterizes Arecibo's unique tropical environment.
As we transition into September, Arecibo, Puerto Rico, experiences a notable dip in average wind speed, plummeting to 3.2 m/s (7 mph), which is the lowest of the year. This drop is particularly striking when compared to the breezier summer months, where July showcased speeds of 5.1 m/s (11 mph) and August maintained a consistent 4.6 m/s (10 mph). The gentle September winds usher in a quieter atmosphere, hinting at the calm that precedes the busier fall season. As the year progresses into October, these winds remain steady, yet subdued, mirroring the tranquil essence of Arecibo's coastal charm during this time.
Weather in Arecibo varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Arecibo, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present contrasting weather experiences. In September, average temperatures range from a warm minimum of 24°C (75°F) to a maximum of 32°C (90°F), accompanied by high humidity levels of 79% and substantial rainfall of 205 mm (8.1 in) over 23 days. In comparison, January features milder conditions with temperatures dropping to a minimum of 18°C (65°F) and peaking at 29°C (84°F). This month sees significantly less precipitation at 41 mm (1.6 in) across just 11 days and slightly lower humidity at 76%. For a closer look at January's specific conditions, you can refer to Arecibo weather in January.
When comparing the weather in September and February, notable differences emerge. September tends to be warmer, with average temperatures around 27°C (81°F) and maximums reaching 32°C (90°F), while February averages a cooler 24°C (76°F), peaking at 30°C (86°F). Additionally, September experiences significantly higher precipitation, with 205 mm (8.1 in) over 23 days, in contrast to February's milder 47 mm (1.8 in) across only 13 days. Humidity levels are also slightly higher in September at 79%, compared to February’s 75%. For more detailed insights into February's weather in Arecibo, visit Arecibo weather in February.
When comparing the weather in September and March, notable differences emerge in temperature and precipitation. September tends to be warmer, with average temperatures ranging from a minimum of 24°C (75°F) to a maximum of 32°C (90°F), while March features slightly cooler temperatures, ranging from a minimum of 20°C (68°F) to a maximum of 30°C (86°F). In terms of precipitation, September is significantly wetter, receiving 205 mm (8.1 in) over 23 days, compared to March's 87 mm (3.4 in) over just 16 days. Additionally, humidity levels are moderately high in both months, with September at 79% and March at 74%. For more detailed information, you can check out Arecibo weather in March.
In comparing the weather conditions of September and April, September tends to be warmer and much wetter. The average temperature in September is around 27°C (81°F), with highs reaching 32°C (90°F), while April has a slightly cooler average of 25°C (77°F) and a maximum of 30°C (87°F). Furthermore, September experiences significant rainfall, with 205 mm (8.1 in) spread over 23 days, compared to April's 79 mm (3.1 in) over just 13 days. Humidity levels are also slightly higher in September at 79%, compared to 75% in April. For more detailed information about Arecibo's weather in April, you can visit Arecibo weather in April.
When comparing the weather in September and May, both months experience warm temperatures, with September having a slightly higher average temperature of 27°C (81°F) compared to May’s 26°C (79°F). The maximum temperatures are similar, reaching 32°C (90°F) in September and 32°C (91°F) in May. However, September is notably wetter, receiving 205 mm (8.1 in) of precipitation over 23 days, while May sees only 98 mm (3.9 in) over 16 days. Additionally, September has a higher humidity level at 79%, compared to May's 75%. For more detailed information, you can check out Arecibo weather in May.
When comparing the weather in September and June, both months exhibit warm temperatures, with September having a slightly higher average minimum temperature of 24°C (75°F) compared to June's 23°C (74°F). While both months have similar average daily temperatures around 27°C (80°F), September tends to be more humid at 79%, compared to June's 77%. Precipitation also differs significantly; September receives much more rain at 205 mm (8.1 in) over 23 days, in contrast to June's 90 mm (3.5 in) over just 14 days. For more detailed insights on June weather in Arecibo, you can check this link: Arecibo weather in June.
In comparing the weather between September and July, both months feature similar temperature ranges, with minimums at 24°C (75°F), averages at 27°C (81°F), and maximums reaching 32°C (90°F). However, September experiences significantly higher precipitation, totaling 205 mm (8.1 in) over 23 days, compared to July's 91 mm (3.6 in) over just 16 days. Humidity levels are also comparable, with September at 79% and July slightly higher at 80%. For a detailed look at July's weather, you can check out Arecibo weather in July.
In comparing the weather between August and September, we notice that both months have similar temperature ranges, with minimum temperatures of 24°C (75°F), average temperatures of 27°C (81°F), and maximum temperatures reaching 32°C (90°F). However, September is significantly wetter, with a precipitation total of 205 mm (8.1 in) falling over 23 days, compared to August's 104 mm (4.1 in) over 19 days. In terms of humidity, September's average humidity is slightly lower at 79%, while August hovers around 80%. For more detailed insights on August weather, you can visit Arecibo weather in August.
In comparing the weather of September and October, both months experience relatively warm temperatures, with September having a slight edge in maximum temperatures, reaching up to 32°C (90°F) compared to October's 31°C (89°F). While the average temperatures remain quite similar, with both months averaging around 27°C (81°F), September is marked by higher humidity levels at 79%, compared to October's 78%. Precipitation also sees a decrease in October, with 161 mm (6.4 in) of rain over 23 days, compared to September's 205 mm (8.1 in) over the same number of days. For more detailed information, you can check out Arecibo weather in October.
In comparing the weather between September and November, we observe a slight decrease in temperature and humidity. In September, temperatures range from a minimum of 24°C (75°F) to a maximum of 32°C (90°F), with an average of 27°C (81°F). November, on the other hand, sees temperatures drop slightly, with a minimum of 22°C (72°F), an average of 26°C (79°F), and a maximum of 31°C (88°F). Additionally, September experiences significantly heavier rainfall, totaling 205 mm (8.1 in) over 23 days, compared to November's 109 mm (4.3 in) across 18 days. For more detailed insights, check out Arecibo weather in November.
September and December exhibit notable differences in weather patterns. September tends to be warmer with average temperatures reaching around 27°C (81°F) and maximums climbing to 32°C (90°F), while December cools down slightly with an average of 25°C (77°F). In addition, September experiences significantly higher precipitation, with 205 mm (8.1 in) over 23 days, compared to December's 45 mm (1.8 in) across just 15 days. Both months have relatively high humidity, but September maintains a slightly higher level at 79% compared to December's 76%. For more detailed information about December weather in Arecibo, you can visit Arecibo weather in December.
As September unfolds in Arecibo, the warmth and humidity create a distinctive atmosphere compared to the rest of the year. With average temperatures hovering around 27°C (81°F), the days feel balmy, yet the month is significantly marked by frequent rainfall, accumulating over 205 mm across nearly three weeks. This increased precipitation and higher humidity levels give September a lush, vibrant feel as the lush landscape thrives. Travelers and locals alike can experience the unique charm of post-rain vistas amidst the warmth. For a deeper understanding of what to expect throughout the year, visit Arecibo Climate.