Last updated: August 23, 2025
In Santiago, Costa Rica, the average temperature in December hovers around 21°C (71°F), providing a pleasant climate for visitors. Expect temperatures to range from a comfortable 16°C (62°F) to a warm 27°C (80°F). However, be prepared for wet weather, as the region receives an average precipitation of 253 mm (10.0 in) over 28 days, and humidity levels tend to be around 72%.
In December in Santiago, the average temperature is 21°C (71°F), with maximums reaching up to 27°C (80°F) and minimums dipping as low as 16°C (62°F). This pleasant climate makes it an ideal time for travelers to explore and enjoy all that Santiago has to offer.
In Santiago in December, the total precipitation amount is 253 mm (10.0 in) spread over a period of 28 days.
In Santiago in December, humidity is 72%. With an average temperature of 21°C (71°F), this humidity feels like a warm embrace, creating a thick, sultry atmosphere that can be quite heavy for traveling.
In Santiago in December, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Santiago.
UV Risk Categories
Weather in Santiago varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Santiago, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 21°C (71°F) | 116 mm (4.6 inches) | 68% | extreme |
| February Weather | 22°C (71°F) | 65 mm (2.5 inches) | 68% | extreme |
| March Weather | 22°C (72°F) | 74 mm (2.9 inches) | 66% | extreme |
| April Weather | 22°C (72°F) | 253 mm (10.0 inches) | 67% | extreme |
| May Weather | 22°C (72°F) | 706 mm (27.8 inches) | 69% | extreme |
| June Weather | 22°C (72°F) | 651 mm (25.6 inches) | 84% | extreme |
| July Weather | 22°C (72°F) | 682 mm (26.9 inches) | 85% | extreme |
| August Weather | 22°C (71°F) | 762 mm (30.0 inches) | 82% | extreme |
| September Weather | 21°C (71°F) | 853 mm (33.6 inches) | 81% | extreme |
| October Weather | 21°C (70°F) | 873 mm (34.4 inches) | 80% | extreme |
| November Weather | 21°C (71°F) | 503 mm (19.8 inches) | 80% | extreme |
| December Weather | 21°C (71°F) | 253 mm (10.0 inches) | 72% | very high |