Last updated: August 22, 2025
In December, the average temperature in San Francisco, Argentina hovers around 24°C (76°F). However, temperatures can swing from a chilly 9°C (48°F) to a blistering 39°C (103°F). Expect about 95 mm (3.7 in) of precipitation spread over 8 days, contributing to an average humidity of 57%. Stay prepared for the climate’s range!
In December in San Francisco, the average temperature is 24°C (76°F). Maximum temperatures can reach as high as 39°C (103°F), while minimum temperatures can drop to a chilly 9°C (48°F). It's advisable to pack for a range of weather conditions, ensuring you stay comfortable throughout your travels.
In San Francisco in December, the total precipitation amount is 95 mm (3.7 in) spread over 8 days.
In San Francisco in December humidity is 57%. With an average temperature of 24°C (76°F), this humidity feels like a warm embrace, making it perfect for leisurely strolls but also a bit sticky for those unaccustomed to the climate, so travelers should stay hydrated and take occasional breaks in the shade.
In San Francisco in December, the maximum UV index is 14, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, so it's crucial to take precautions. For the detailed hourly UV index in San Francisco, you can check here.
UV Risk Categories
Weather in San Francisco varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in San Francisco, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 25°C (78°F) | 105 mm (4.1 inches) | 51% | extreme |
| February Weather | 24°C (75°F) | 70 mm (2.8 inches) | 57% | extreme |
| March Weather | 22°C (72°F) | 90 mm (3.5 inches) | 65% | extreme |
| April Weather | 19°C (67°F) | 120 mm (4.7 inches) | 76% | very high |
| May Weather | 15°C (59°F) | 61 mm (2.4 inches) | 83% | high |
| June Weather | 12°C (54°F) | 19 mm (0.7 inches) | 78% | moderate |
| July Weather | 11°C (53°F) | 19 mm (0.8 inches) | 58% | moderate |
| August Weather | 14°C (57°F) | 14 mm (0.5 inches) | 54% | high |
| September Weather | 17°C (63°F) | 37 mm (1.5 inches) | 59% | very high |
| October Weather | 19°C (67°F) | 89 mm (3.5 inches) | 50% | extreme |
| November Weather | 23°C (73°F) | 84 mm (3.3 inches) | 53% | extreme |
| December Weather | 24°C (76°F) | 95 mm (3.7 inches) | 57% | extreme |