Last updated: March 2, 2024
The weather in San Marcos, United States, during December is characterized by an average temperature of 14°C (57°F). Highs can soar to 25°C (77°F), while lows may dip to 4°C (40°F). Typically, the humidity level in San Marcos throughout December hovers around 74%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In December, San Marcos averages 70 mm (2.7 inches) of rainfall, typically over the course of 6 rainy days. The month enjoys an average of 9 hours 59 minutes of daylight, with the sun shining for approximately 7 hours 20 minutes each day. Additionally, there is a 48% probability of sunny days during this period.
Precipitation
Rainy days
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Chance of sun
In December, the UV Index in San Marcos reaches a maximum of 4, indicating a level of Moderate exposure. The most intense UV radiation typically occurs between 11:00 and 13:00, during which unprotected skin may burn in as little as 30 minutes.
| 07:00 | 08:00 | 09:00 | 10:00 | 11:00 | 12:00 | 13:00 | 14:00 | 15:00 | 16:00 | 17:00 | 18:00 | 19:00 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UVI | 1 | 1 | 2 | 3 | 4 | 4 | 3 | 2 | 1 | 1 | 0 | 0 | 0 |
| Exposure | Low | Moderate | Low | ||||||||||
| Time to burn | 45 min | 30 min | 45 min | ||||||||||