Last updated: August 27, 2025
In December, the average temperature in Santiago, Mexico is a mild 13°C (55°F). However, be prepared for a range of temperatures, as the minimum can drop to -7°C (20°F) while the maximum can climb to 29°C (84°F). During this time, you can expect 50 mm (2.0 in) of precipitation spread over 6 days, and with an average humidity of 80%, it’s a good idea to pack accordingly!
In December in Santiago, the average temperature is 13°C (55°F), with maximums reaching 29°C (84°F) and minimums dropping as low as -7°C (20°F). Be sure to pack layers to adapt to the wide temperature range during your travels.
In Santiago in December, the precipitation amount is 50 mm (2.0 in) over the course of 6 days.
In Santiago in December humidity is 80%. With an average temperature of 13°C (55°F), this humidity feels like a damp blanket wrapping around you, making any outdoor activity feel stifling and heavy, which can lead to fatigue for travelers unaccustomed to such moist conditions.
In Santiago in December, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Santiago, you can refer to this Hourly UV Index in Santiago.
UV Risk Categories
Weather in Santiago varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Santiago, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 11°C (53°F) | 45 mm (1.8 inches) | 75% | high |
| February Weather | 14°C (57°F) | 78 mm (3.1 inches) | 70% | very high |
| March Weather | 17°C (62°F) | 98 mm (3.9 inches) | 65% | extreme |
| April Weather | 19°C (67°F) | 187 mm (7.4 inches) | 59% | extreme |
| May Weather | 22°C (72°F) | 193 mm (7.6 inches) | 66% | extreme |
| June Weather | 23°C (74°F) | 93 mm (3.7 inches) | 71% | extreme |
| July Weather | 23°C (74°F) | 120 mm (4.7 inches) | 57% | extreme |
| August Weather | 24°C (75°F) | 30 mm (1.2 inches) | 58% | extreme |
| September Weather | 22°C (71°F) | 191 mm (7.5 inches) | 72% | extreme |
| October Weather | 19°C (66°F) | 73 mm (2.9 inches) | 76% | extreme |
| November Weather | 15°C (59°F) | 54 mm (2.1 inches) | 81% | very high |
| December Weather | 13°C (55°F) | 50 mm (2.0 inches) | 80% | high |