Last updated: August 27, 2025
In December, the average temperature in San Mateo, Mexico hovers around 12°C (54°F). Visitors should be prepared for a range of temperatures, as it can dip to a chilly -2°C (28°F) at its lowest and reach a pleasant 25°C (77°F) at its highest. Expect a mild level of precipitation, with about 35 mm (1.4 in) spread over 7 days, and note that the air tends to feel quite humid, with an average humidity of 91%.
In December in San Mateo, the average temperature is 12°C (54°F). Maximum temperatures can reach 25°C (77°F), while minimums can drop as low as -2°C (28°F). It’s advisable to pack layers to prepare for fluctuating temperatures during your travels.
In San Mateo in December, the precipitation amount is 35 mm (1.4 in) over the course of 7 days.
In San Mateo in December, humidity is 91%. With an average temperature of 12°C (54°F), this humidity feels like a damp blanket wrapping around you, making even short walks feel heavy and sluggish, which can be quite challenging for travelers looking to explore the area comfortably.
In San Mateo in December, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in San Mateo.
UV Risk Categories
Weather in San Mateo varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in San Mateo, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 12°C (53°F) | 57 mm (2.2 inches) | 88% | very high |
| February Weather | 14°C (57°F) | 50 mm (2.0 inches) | 86% | extreme |
| March Weather | 15°C (60°F) | 74 mm (2.9 inches) | 83% | extreme |
| April Weather | 17°C (63°F) | 87 mm (3.4 inches) | 80% | extreme |
| May Weather | 19°C (66°F) | 144 mm (5.7 inches) | 82% | extreme |
| June Weather | 18°C (65°F) | 247 mm (9.7 inches) | 79% | extreme |
| July Weather | 18°C (64°F) | 192 mm (7.5 inches) | 72% | extreme |
| August Weather | 18°C (64°F) | 267 mm (10.5 inches) | 74% | extreme |
| September Weather | 18°C (64°F) | 291 mm (11.5 inches) | 84% | extreme |
| October Weather | 16°C (62°F) | 250 mm (9.8 inches) | 92% | extreme |
| November Weather | 14°C (57°F) | 92 mm (3.6 inches) | 91% | very high |
| December Weather | 12°C (54°F) | 35 mm (1.4 inches) | 91% | very high |