San Juan in December
In December, San Juan averages 29°C (84°F) during the day and 22°C (72°F) at night, with around 12 days of rain (110 mm total).
High seasonConditions are warm and beach-friendly. Plan for unsettled weather and bring rain gear.
December offers comfortable temperatures in San Juan, with some rain to plan around.
How December compares to the rest of the year in San Juan
December is one of the coolest months in San Juan (10th of 12) and moderately rainy compared to the rest of the year (8th of 12). Daytime temperature runs 1°C below the annual average (30°C). December runs 1°C cooler than November (30°C) and cools 1°C in January (28°C).
December sunrise & sunset in San Juan
Times shown for San Juan local time (America/Puerto_Rico), calculated for the 15th of December. They shift by a few minutes day to day across the month.
Photography light in San Juan — December
Golden-hour and blue-hour windows for the 15th of December, in San Juan's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).
📅 When to book — San Juan in December
Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on December's tier (High season) and San Juan's popularity.
Crowds & pricing — December in San Juan
This is a busy month in San Juan — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.
Why this tier: comfortable tourism weather Christmas / New Year travel surge
Sun & mosquito risk — December in San Juan
UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.
Sea temperature in San Juan — December
Across the year San Juan's sea swings from 26.5°C (February) to 30.4°C (October) — December sits at 28.3°C.
San Juan in other months
| Month | Avg high | Avg low | Rainfall | Rain days | Snow days |
|---|---|---|---|---|---|
| January | 28°C / 82°F | 21°C / 70°F | 75 mm | 11 | — |
| February | 28°C / 82°F | 21°C / 70°F | 55 mm | 9 | — |
| March | 29°C / 84°F | 22°C / 72°F | 55 mm | 9 | — |
| April | 29°C / 84°F | 23°C / 73°F | 110 mm | 11 | — |
| May | 30°C / 86°F | 24°C / 75°F | 155 mm | 14 | — |
| June | 31°C / 88°F | 25°C / 77°F | 130 mm | 14 | — |
| July | 31°C / 88°F | 25°C / 77°F | 150 mm | 16 | — |
| August | 32°C / 90°F | 25°C / 77°F | 165 mm | 16 | — |
| September | 31°C / 88°F | 25°C / 77°F | 145 mm | 15 | — |
| October | 31°C / 88°F | 24°C / 75°F | 130 mm | 13 | — |
| November | 30°C / 86°F | 23°C / 73°F | 140 mm | 13 | — |
| December | 29°C / 84°F | 22°C / 72°F | 110 mm | 12 | — |
Other cities with similar December weather
🌍 See the full ranked list of climate twins for San Juan in December →
Frequently asked questions
How hot is San Juan in December?
In December, San Juan averages a high of 29°C (84°F) and a low of 22°C (72°F) — generally warm.
Does it rain a lot in San Juan in December?
December can be fairly wet in San Juan, with about 12 rainy days on average.
Is December a good time to visit San Juan?
December is warm. It suits travelers who are comfortable with warm weather; check the month-by-month ranking to compare it against the rest of the year.
What should I pack for San Juan in December?
Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full December packing list for San Juan for a complete, climate-based checklist.
Check the live 10-day forecast and sunrise/sunset.