Last updated: June 24, 2025
In December, the average temperature in San Luis, United States hovers around -4°C (25°F), with lows plunging to a chilly -24°C (-11°F) and highs reaching up to 14°C (57°F). Expect about 23 mm (0.9 in) of precipitation spread over 6 days, contributing to an average humidity level of 85%. Stay warm and prepared!
In December in San Luis, the average temperature is -4°C (25°F). Maximum temperatures can reach 14°C (57°F), while minimums can dip as low as -24°C (-11°F). Travelers should be prepared for significant temperature fluctuations, ensuring they pack appropriately for cold conditions.
In San Luis in December, the precipitation amount is 23 mm (0.9 in) spread over 6 days.
In San Luis in December, humidity is 85%. With an average temperature of -4°C (25°F), this humidity feels like a damp chill clinging to your skin, making travel outside uncomfortable and leaving you feeling cold and clammy despite the freezing temperatures.
In San Luis in December, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in San Luis for better planning.
UV Risk Categories
Weather in San Luis varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in San Luis, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -5°C (23°F) | 23 mm (0.9 inches) | 84% | moderate |
| February Weather | -4°C (25°F) | 25 mm (1.0 inches) | 84% | high |
| March Weather | 1°C (34°F) | 37 mm (1.5 inches) | 74% | very high |
| April Weather | 5°C (42°F) | 35 mm (1.4 inches) | 68% | extreme |
| May Weather | 10°C (51°F) | 42 mm (1.6 inches) | 62% | extreme |
| June Weather | 16°C (62°F) | 28 mm (1.1 inches) | 55% | extreme |
| July Weather | 18°C (65°F) | 71 mm (2.8 inches) | 54% | extreme |
| August Weather | 17°C (63°F) | 45 mm (1.8 inches) | 61% | extreme |
| September Weather | 14°C (57°F) | 31 mm (1.2 inches) | 70% | extreme |
| October Weather | 7°C (45°F) | 27 mm (1.1 inches) | 78% | very high |
| November Weather | 2°C (35°F) | 17 mm (0.7 inches) | 81% | moderate |
| December Weather | -4°C (25°F) | 23 mm (0.9 inches) | 85% | moderate |