Last updated: January 18, 2025
San Juan, Puerto Rico, exhibits a tropical savanna climate classified under the Koppen-Geiger system as Am. Characterized by warm temperatures year-round, the city experiences an average of 26°C (80°F), with minimum temperatures reaching 21°C (69°F) in January and peaking at 32°C (90°F) in September. This climate pattern contributes to a vibrant ecosystem and cultural richness, making San Juan a dynamic locale within the Caribbean region.
San Juan, Puerto Rico, displays relatively stable temperature patterns throughout the year, with warm and balmy conditions defining each month. The coldest months, January and February, have minimum temperatures around 21°C (69°F) and average highs of 29°C (85°F), leading to a comfortable winter climate. As spring progresses into April and May, temperatures gradually rise, with averages reaching 27°C (80°F) and maximums peaking at 32°C (90°F). The summer months from June to September present the warmest weather, maintaining consistent averages around 28°C (82°F) and maximum temperatures consistently hitting 32°C (90°F). As autumn approaches, temperatures slightly moderate, with November and December averaging 26°C (78°F) but still enjoying warm days. Overall, San Juan experiences a tropical warmth throughout the year, punctuated by minor fluctuations and a distinct dry season in the winter months.
San Juan experiences a range of temperatures throughout the year, with a minimum of 21°C (69°F) in January and peaking at 32°C (90°F) in September. For more detailed information on monthly temperatures in San Juan, visit monthly temperatures in San Juan.
San Juan, Puerto Rico, experiences a distinctive precipitation pattern characterized by a distinct wet season that spans from May to November. The annual rainfall begins modestly in the early months, with January and February receiving 38 mm (1.5 in) and 43 mm (1.7 in), respectively. However, as the year progresses, rainfall increases, peaking significantly in September with 173 mm (6.8 in)—the wettest month—and frequently touching 99 mm (3.9 in) in August. This marked increase in precipitation correlates with the Atlantic hurricane season, which often impacts the region.
Throughout the wet season, the number of rainy days also rises, particularly in September, which often sees around 23 days of precipitation. Additionally, July and August both average 18 rainy days, contributing to discomfort during the summer months. Conversely, the dry season during January and February generally features about 12 rainy days, offering a respite from the heavier rains. The precipitation levels and frequency in San Juan contribute to the lush vegetation and tropical landscapes that characterize the beautiful island of Puerto Rico.
San Juan, Puerto Rico, enjoys a generous amount of sunshine throughout the year, with a clear upward trend in sunlight hours as winter transitions into summer. Beginning with 257 hours of sunshine in January, the city gradually increases its sunlight exposure, reaching a peak of 356 hours in May. This trend signals the impending summer, where longer daylight hours and clearer skies become prevalent. The late spring and early summer months of May, June, and July consistently feature more than 340 hours of sunshine, presenting an ideal climate for outdoor activities and tourism.
As the summer gives way to autumn, sunshine hours remain relatively stable but see a slight decline. Notable for its moderate sunshine, September and October each receive around 313 hours, signaling the transition into the wet season and potential cloud cover. However, even in the cooler months like November and December, San Juan retains a respectable 299 to 319 hours of sunshine, ensuring that visitors and residents alike can still enjoy the warm tropical climate. Overall, the consistent availability of sunshine in San Juan not only enhances its appeal as a travel destination but also contributes to the region's vibrant ecosystems.
San Juan, Puerto Rico, experiences a consistently high UV Index throughout the year, reflecting its tropical climate and proximity to the equator. In the winter months, the UV Index starts at 9 in January, categorized as very high, which means that unprotected skin can burn within 15 minutes of sun exposure. As the year progresses into February and March, the UV levels rise significantly, peaking at 11 in February and reaching an extreme 13 from March through June. With burn times as short as 10 minutes, it is essential for residents and visitors alike to adopt sun safety measures during these months to avoid harmful effects from UV radiation.
During the summer, the UV Index remains persistently high, with only minimal fluctuations; it reaches its maximum of 14 in May before slightly decreasing to 12 by October. Notably, the index remains extreme for most of the summer, emphasizing the need for effective sun protection during outdoor activities. As the year draws to a close, UV levels drop to 9 in November and 8 in December, returning to a very high category but still demanding vigilance against sun exposure. The high UV Index in San Juan underscores the importance of sun safety year-round, making it crucial to safeguard skin from potential damage even during the cooler months.
UV Risk Categories
San Juan, Puerto Rico, enjoys a relatively consistent daylight duration throughout the year, largely influenced by its tropical location. In the early months of January and February, the city experiences about 11 hours of daylight, creating a balanced atmosphere for both residents and visitors. As spring approaches, daylight hours gradually extend to 12 hours from March through May, indicating the transition toward the summer season and allowing ample time for outdoor activities and exploration.
Summer months of June and July see a peak in daylight duration, with each day offering approximately 13 hours of sunlight, which benefits the vibrant local culture and tourism. However, as the summer gives way to autumn, the daylight duration returns to 12 hours in August and September, followed by a decline to 11 hours in the final months of the year from October to December, echoing the patterns seen earlier in the year. This consistent daylight availability contributes to the region's appealing climate, enhancing the outdoor lifestyle that characterizes San Juan.
San Juan, Puerto Rico experiences a tropical climate characterized by warm temperatures and seasonal rainfall. Monthly temperatures range from a mild 21°C (69°F) in January to a peak of 32°C (90°F) from May to September. Rainfall is most abundant in September with an average of 173 mm (6.8 in), while the dry season generally falls between January and March. The region enjoys ample sunshine, peaking in May with 356 hours, making it an attractive destination year-round. For more details, visit San Juan climate.
In conclusion, San Juan, Puerto Rico, presents a captivating climate characterized by warm temperatures, abundant sunshine, and high UV levels year-round. The city's tropical savanna climate not only fosters a vibrant ecosystem but also supports a dynamic outdoor lifestyle, with residents and visitors alike benefiting from its consistent daylight hours. Seasonal trends reveal variations in precipitation and sunshine, highlighting the importance of sun safety during the intense summer months. Overall, understanding these climatic elements enhances the appreciation of San Juan’s natural beauty and its allure as a premier Caribbean destination.