San Juan in January
In January, San Juan averages 28°C (82°F) during the day and 21°C (70°F) at night, with around 11 days of rain (75 mm total).
ShoulderConditions are warm and beach-friendly. Plan for unsettled weather and bring rain gear.
January offers comfortable temperatures in San Juan, with some rain to plan around.
How January compares to the rest of the year in San Juan
January is one of the coolest months in San Juan (11th of 12) and moderately rainy compared to the rest of the year (9th of 12). Daytime temperature runs 2°C below the annual average (30°C). January runs 1°C cooler than December (29°C) and stays flat into February.
January sunrise & sunset in San Juan
Times shown for San Juan local time (America/Puerto_Rico), calculated for the 15th of January. They shift by a few minutes day to day across the month.
Photography light in San Juan — January
Golden-hour and blue-hour windows for the 15th of January, in San Juan's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).
📅 When to book — San Juan in January
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 January's tier (Shoulder) and San Juan's popularity.
Crowds & pricing — January in San Juan
San Juan is in a shoulder season month — fewer crowds, slightly lower prices, and a calmer atmosphere than peak weeks. Most major sights stay open with normal hours, though a handful of seasonal restaurants or boat trips may run reduced schedules. Many regulars consider these months the best time to visit because you trade a small amount of weather reliability for a much more pleasant on-the-ground experience.
Why this tier: comfortable tourism weather
Sun & mosquito risk — January 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 — January
Across the year San Juan's sea swings from 26.5°C (February) to 30.4°C (October) — January sits at 27°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 January weather
🌍 See the full ranked list of climate twins for San Juan in January →
Frequently asked questions
How hot is San Juan in January?
In January, San Juan averages a high of 28°C (82°F) and a low of 21°C (70°F) — generally warm.
Does it rain a lot in San Juan in January?
January can be fairly wet in San Juan, with about 11 rainy days on average.
Is January a good time to visit San Juan?
January 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 January?
Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full January packing list for San Juan for a complete, climate-based checklist.
Check the live 10-day forecast and sunrise/sunset.