Last updated: August 27, 2025
In December, the average temperature in San Antonio, Mexico hovers around 14°C (58°F), with extremes ranging from a chilly -1°C (30°F) to a pleasant 28°C (83°F). Visitors can expect a slight drizzle, with only 4 mm (0.2 in) of precipitation spread over 0 days. Humidity remains high at an average of 91%, adding to the atmospheric charm of the region.
In December in San Antonio, the average temperature is 14°C (58°F). Maximums can reach 28°C (83°F), and minimums can be as low as -1°C (30°F). Therefore, travelers should be prepared for a diverse range of weather conditions.
In San Antonio in December, the precipitation amount is 4 mm (0.2 in) over the course of 0 days.
In San Antonio in December humidity is 91%. With an average temperature of 14°C (58°F), this humidity feels like a heavy blanket wrapping around you, making travel a bit uncomfortable as sweat mingles with the cool air, creating an uneasy atmosphere for exploration.
In San Antonio 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 Antonio.
UV Risk Categories
Weather in San Antonio varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in San Antonio, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 14°C (58°F) | 7 mm (0.3 inches) | 88% | very high |
| February Weather | 17°C (62°F) | 6 mm (0.3 inches) | 86% | extreme |
| March Weather | 19°C (66°F) | 13 mm (0.5 inches) | 83% | extreme |
| April Weather | 21°C (70°F) | 18 mm (0.7 inches) | 80% | extreme |
| May Weather | 22°C (72°F) | 36 mm (1.4 inches) | 82% | extreme |
| June Weather | 20°C (69°F) | 127 mm (5.0 inches) | 79% | extreme |
| July Weather | 19°C (67°F) | 96 mm (3.8 inches) | 72% | extreme |
| August Weather | 20°C (68°F) | 102 mm (4.0 inches) | 74% | extreme |
| September Weather | 19°C (66°F) | 131 mm (5.2 inches) | 84% | extreme |
| October Weather | 18°C (64°F) | 67 mm (2.6 inches) | 92% | extreme |
| November Weather | 16°C (61°F) | 20 mm (0.8 inches) | 91% | very high |
| December Weather | 14°C (58°F) | 4 mm (0.2 inches) | 91% | very high |