San Juan Weather in December
December in San Juan averages 29°C (84°F) during the day and 23°C (73°F) at night. Quite a bit of rainfall is typical this month, with around 65 mm (2.6 in) on average. An umbrella is a good idea.
Rainfall in San Juan in December
This month experiences about 21 days of rain according to historical data, averaging 65 mm (2.6 in). Rain is frequent but mostly light this month, with brief showers more common than heavy downpours.
Temperature in San Juan in December
If you're visiting San Juan in December, expect perfect temperatures with highs of 29°C (84°F) and overnight lows of 23°C (73°F). This gives the month a fairly typical daily rhythm, with warmer afternoons and more comfortable nights. At 23°C (73°F) overnight, it stays warm after dark. Light, breathable clothing and good airflow in your room make a noticeable difference.
Sunshine in San Juan in December
Expect sunny days throughout the month, with an estimated 216 hours of sunshine. This makes it a pleasant time to visit San Juan.
Wind Speed in San Juan in December
December has wind speeds averaging 3 m/s (6 knots). You can expect comfortable light winds that steadily move flags and feel mild throughout the day. Since this is an average, daily conditions vary from gentle winds to more active breezes.
Average water temperature in December
The water is 27°C (81°F) this month — warm enough that getting in requires no effort at all. Good conditions for swimming, snorkeling, or just floating around.Our weather planner can help you find worldwide destinations with pleasant weather during this period. January, February, March and December typically offer the best weather for San Juan.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Puerto Rico, check out our San Juan's climate page.
San Juan Temperature in December
Min Temperature
23°C (73°F)
Max Temperature
29°C (84°F)
Water Temperature
27°C (81°F)
Chance of Rain
70%
Precipitation
65 mm (2.6 in)
Rainy days
21 days
Humidity
75%
Windspeed
3 m/s (6 knots)
Sunshine
216 hours
Percentage Sunshine
64%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in San Juan typically stay consistent throughout December, with daily highs averaging around 29°C (84°F). Nights are warm, with lows around 23°C (73°F).
Average temperatures in December
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in December
Historical weather for San Juan in December
Browse day-by-day weather records for San Juan spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
San Juan historical weather extremes in December
According to our 49 years of weather records for San Juan, the following extremes were recorded between 1976 and 2025.
- The hottest December day on record in San Juan reached 34°C (93°F) (December 6, 1989).
- San Juan experienced its chilliest December day on December 15, 2010, reaching only 24°C (75°F).
- Nighttime temperatures dropped to 18°C (64°F) on December 30, 2002, marking the coldest December night on record.
Best Places in Puerto Rico in December
Find out more about the weather in Puerto Rico and which places have the best travel conditions in this month. See all of Puerto Rico in December →
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What to Wear in San Juan in December
Warm temperatures in December make for comfortable sightseeing weather. Pack breathable fabrics like cotton shirts, knee-length shorts or skirts, and comfortable walking shoes. A thin long sleeve for indoor spaces is handy. Rain gear is recommended, you can expect wet weather on multiple days. The water temperature sits at about 27°C (81°F), making it perfect for swimming and water activities. Don't forget to pack your favorite swimwear and perhaps some snorkel gear. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.What To Do in San Juan in December
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Puerto Rico, check out our San Juan's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full San Juan climate overview or explore weather in Puerto Rico.
