Last updated: August 27, 2025
In San Juan, Peru, the average temperature in December hovers around 8°C (47°F). Expect a chilly minimum of -4°C (25°F) and a pleasant maximum of 19°C (67°F). With an average precipitation of 146 mm (5.7 in) spread over 23 days, it's wise to keep an umbrella handy. Additionally, the average humidity sits at a comfortable 82%, adding to the region's unique climate.
In December in San Juan, the average temperature is 8°C (47°F). Maximum temperatures can reach 19°C (67°F) while the minimum can drop as low as -4°C (25°F). Be prepared for a wide range of temperatures during your travels, so pack accordingly!
In San Juan in December, the precipitation amount is 146 mm (5.7 in) distributed over 23 days.
In San Juan in December humidity is 82%. With an average temperature of 8°C (47°F), this humidity feels like a damp chill that seeps into your bones, making outdoor exploration less enjoyable and requiring extra layers to stay warm and comfortable.
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 | 8°C (47°F) | 254 mm (10.0 inches) | 89% | extreme |
| February Weather | 8°C (47°F) | 268 mm (10.6 inches) | 90% | extreme |
| March Weather | 8°C (47°F) | 323 mm (12.7 inches) | 90% | extreme |
| April Weather | 7°C (46°F) | 142 mm (5.6 inches) | 90% | extreme |
| May Weather | 6°C (44°F) | 72 mm (2.8 inches) | 84% | extreme |
| June Weather | 6°C (43°F) | 49 mm (1.9 inches) | 67% | extreme |
| July Weather | 6°C (43°F) | 41 mm (1.6 inches) | 53% | extreme |
| August Weather | 6°C (44°F) | 35 mm (1.4 inches) | 47% | extreme |
| September Weather | 7°C (46°F) | 93 mm (3.7 inches) | 53% | extreme |
| October Weather | 8°C (46°F) | 106 mm (4.2 inches) | 67% | extreme |
| November Weather | 8°C (47°F) | 83 mm (3.3 inches) | 75% | extreme |
| December Weather | 8°C (47°F) | 146 mm (5.7 inches) | 82% | extreme |