Last updated: January 18, 2025
Guaynabo, Puerto Rico, exhibits a tropical rainforest climate as classified by the Köppen-Geiger system (Am), characterized by warm temperatures throughout the year. The climate features a minimum temperature of 19°C (66°F) in January, rising to an average of 26°C (78°F), and reaching peak warmth with a maximum of 32°C (90°F) in September. This stable warm climate contributes to the region's lush vegetation and rich biodiversity, making Guaynabo a unique habitat within the Caribbean.
In Guaynabo, Puerto Rico, temperature patterns reflect a consistently warm tropical climate with slight variations across the months. The year begins with mild temperatures in January, where minimums hover around 19°C (66°F) and average at 24°C (76°F), gradually warming as spring approaches. By April and May, temperatures rise significantly, with average temperatures reaching 25°C (77°F) and 26°C (79°F), enticing the onset of summer. The heat peaks in September, when maximum temperatures can reach up to 32°C (90°F), creating a warm season that extends through summer months, characterized by high humidity. As the year transitions into late fall and winter, temperatures trend downward slightly, yet remain comfortably warm, with minimums ranging from 21°C to 22°C (71°F to 72°F) in December. Overall, Guaynabo experiences a relatively stable warm climate throughout the year, punctuated by a subtle seasonal progression in temperature.
Guaynabo experiences a range of temperatures throughout the year, with a minimum of 19°C (66°F) in January and a maximum of 32°C (90°F) in September. This climate variation presents a warm environment ideal for outdoor activities year-round. For more detailed information, you can refer to the monthly temperatures in Guaynabo here.
Guaynabo, Puerto Rico, experiences significant variability in precipitation throughout the year, showcasing a distinct wet season typically occurring from May through October. This pattern begins with moderate rainfall in the early months, with January seeing 48 mm (1.9 in) and February slightly increasing to 53 mm (2.1 in). As spring unfolds, March and April witness an uptick to 80 mm (3.2 in) and 77 mm (3.0 in) respectively, paving the way for the summer deluge. By July and August, rainfall peaks dramatically, reaching 124 mm (4.9 in) and 130 mm (5.1 in), which coincides with the highest frequency of rainy days, particularly in August with 25 days of precipitation.
September marks the climax of the wet season, as precipitation skyrockets to a hefty 200 mm (7.9 in), coupled with 27 rainy days, reflecting the impact of tropical storms and hurricanes typical of the region. Following this peak, precipitation begins to taper off in October and November, recording 183 mm (7.2 in) and 120 mm (4.7 in) respectively, as the drier months approach. December offers some relief with a decrease to 66 mm (2.6 in) and about 22 rainy days, but the year overall remains classified as wet, underlining the tropical rainforest climate that Guaynabo embodies.
In Guaynabo, Puerto Rico, sunshine duration exhibits a clear seasonal trend, beginning with a gradual increase from winter into summer. January starts the year with 257 hours of sunshine, which is modest compared to the sunnier months that follow. By February, sunlight begins to intensify, reaching 303 hours, and continues to rise appreciably in March and April, both recording 346 hours. This trend peaks in May, where the region enjoys a delightful 356 hours of sunshine, marking it as a standout month for sun seekers. The summer months of June through August maintain high levels of sunshine, fluctuating between 343 to 356 hours, providing ample opportunity for outdoor activities against the backdrop of tropical greenery.
As the year transitions into the fall, sunshine hours begin to taper off slightly. September and October each receive 313 hours of sun, while November sees a further decrease to 299 hours. Nevertheless, sunlight remains relatively abundant compared to the winter months. December closes the year with 319 hours of sunshine, leading to a balanced distribution of sunny days throughout the year. Overall, Guaynabo enjoys a favorable climate with a noticeable peak during late spring to summer, making it an enticing destination year-round for those drawn to warm and sunny weather.
The UV Index in Guaynabo, Puerto Rico, illustrates the region's exposure to harmful ultraviolet radiation throughout the year, consistently reflecting values in the very high to extreme categories. January starts the year with a UV Index of 9, indicating a very high level of UV exposure, where it is recommended to limit unprotected sun exposure to about 15 minutes. As the year progresses into February, the UV Index escalates to 11 and remains in the extreme category for the next several months, peaking at 14 in May. This consistently high UV exposure underscores a need for sun protection during outdoor activities, particularly as the burn time decreases to just 10 minutes in the spring and summer.
This trend of heightened UV radiation continues throughout the summer, with the index stabilizing around 12 to 13 from June to September. October sees a slight reduction to 12, but UV exposure remains significant, requiring ongoing protective measures. As the year winds down, November sees a drop to a UV Index of 9 (very high), and December closes the year at 8, still warranting caution. Overall, Guaynabo's UV Index highlights the importance of sun safety practices year-round, particularly from February through October when the risk of skin damage is at its highest.
UV Risk Categories
In Guaynabo, Puerto Rico, daylight duration exhibits a steady and predictable rhythm throughout the year, with only slight variations. January and February each see about 11 hours of daylight, providing a consistent experience for residents and visitors. As spring approaches, daylight begins to increase, reaching 12 hours in March and persisting through May. This period allows for ample sunlight, which is beneficial for outdoor activities and the region’s lush ecosystems.
The summer months of June and July mark the peak of daylight, offering 13 hours which contributes to longer evenings and vibrant sunsets. Following this, daylight duration begins to taper off with August dropping back to 12 hours, and further decreasing to 11 hours in October, November, and December. Despite these seasonal fluctuations, Guaynabo maintains a relatively consistent amount of daylight, with residents enjoying nearly year-round opportunities for outdoor engagement under the ample Caribbean sun.
Guaynabo, Puerto Rico, enjoys a tropical climate characterized by warm temperatures and distinct wet and dry seasons. Monthly average temperatures range from a mild 24°C (76°F) in winter to a warm 27°C (81°F) during summer. Rainfall peaks in September, with an average of 200 mm (7.9 in), while January receives the least at 48 mm (1.9 in). The region boasts plentiful sunshine, particularly in May with a high of 356 hours. For more detailed information, visit Guaynabo climate.
In conclusion, Guaynabo, Puerto Rico, presents a remarkable climate characterized by warm temperatures, significant precipitation, ample sunshine, and notable UV exposure throughout the year. With a tropical rainforest climate, the region enjoys a consistent pattern of 11 to 13 hours of daylight, enhancing the availability of sunlight for both residents and visitors. Seasonal trends highlight the intensity of summer warmth and rainfall, emphasizing the importance of sun protection during periods of high UV exposure. Together, these climatic features contribute to Guaynabo's rich biodiversity and vibrant outdoor culture, making it an attractive destination for those seeking both adventure and relaxation in a tropical paradise.