Last updated: August 27, 2025
In San Juan, Peru, the average temperature in December hovers around 13°C (55°F), with a minimum of 6°C (44°F) and a maximum soaring to 19°C (66°F). Expect high humidity levels at 87% and prepare for precipitation totaling 129 mm (5.1 in) over about 26 days. Enjoy the uniquely moody weather of this charming destination!
In December in San Juan, the average temperature is 13°C (55°F). The maximum can reach 19°C (66°F) and the minimum can be as low as 6°C (44°F). This mild climate makes San Juan a pleasant destination for travelers looking to explore its sights comfortably.
In San Juan in December, the total precipitation amount is 129 mm (5.1 in) over a span of 26 days.
In San Juan in December, humidity is 87%. With an average temperature of 13°C (55°F), this humidity feels like a heavy blanket wrapping around you, making travel sluggish and slightly uncomfortable, as each step seems to cling to the damp air.
In San Juan in December, the maximum UV index is 18, which corresponds to an extreme exposure category. This means that the time to burn is just 10 minutes. For more detailed information, you can check the hourly UV index in San Juan.
UV Risk Categories
Weather in San Juan varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in San Juan, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 12°C (55°F) | 229 mm (9.0 inches) | 89% | extreme |
| February Weather | 13°C (55°F) | 244 mm (9.6 inches) | 89% | extreme |
| March Weather | 13°C (55°F) | 246 mm (9.7 inches) | 90% | extreme |
| April Weather | 13°C (55°F) | 125 mm (4.9 inches) | 89% | extreme |
| May Weather | 12°C (55°F) | 60 mm (2.3 inches) | 83% | extreme |
| June Weather | 12°C (55°F) | 23 mm (0.9 inches) | 69% | extreme |
| July Weather | 13°C (55°F) | 19 mm (0.7 inches) | 56% | extreme |
| August Weather | 13°C (55°F) | 26 mm (1.0 inches) | 50% | extreme |
| September Weather | 13°C (56°F) | 72 mm (2.9 inches) | 53% | extreme |
| October Weather | 13°C (55°F) | 99 mm (3.9 inches) | 68% | extreme |
| November Weather | 13°C (56°F) | 76 mm (3.0 inches) | 81% | extreme |
| December Weather | 13°C (55°F) | 129 mm (5.1 inches) | 87% | extreme |