San Juan Weather in December
December in San Juan brings very high temperatures around 32°C (90°F) during the day, dropping to 17°C (63°F) at night, with the most rainfall of the year.
Rainfall in San Juan in December
Expect frequent showers this month, so make sure to have an umbrella to keep yourself dry. You can typically expect 4 days of rain this month, averaging around 40 mm (1.6 in). Although rain is not especially frequent, individual showers can still be quite heavy.
Temperature in San Juan in December
December in San Juan brings very high temperatures, with highs of 32°C (90°F) and nights around 17°C (63°F). Sunshine and humidity can make it feel even warmer than the raw temperature suggests. Nights cool down to 17°C (63°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions.
Sunshine in San Juan in December
The days are predominantly sunny, with an estimated total of around 350 hours of sunshine. These sun-filled days are perfect for playing sports, visiting parks, or going for a bike ride.Our weather planner can help you find worldwide destinations with pleasant weather during this period. March, April, May, June, July, August, September and October typically offer the best weather for San Juan.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Argentina, check out our San Juan's climate page.
San Juan Temperature in December
Min Temperature
17°C (63°F)
Max Temperature
32°C (90°F)
Chance of Rain
13%
Precipitation
40 mm (1.6 in)
Rainy days
4 days
Humidity
40%
Sunshine
350 hours
Percentage Sunshine
80%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in San Juan typically stay consistent throughout December, with daily highs averaging around 32°C (90°F). Nights are pleasant, with lows typically ranging from 17°C (63°F) to 20°C (68°F).
Average temperatures in December
Historical weather for San Juan in December
Browse day-by-day weather records for San Juan spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
San Juan historical weather extremes in December
Our historical data for San Juan spans 1976 to 2025, revealing these weather extremes.
- San Juan recorded its highest December temperature of 46°C (115°F) on December 20, 1995.
- San Juan registered its coldest December night on December 13, 2010, with temperatures dropping to 6°C (43°F).
Best Places in Argentina in December
Find out more about the weather in Argentina and which places have the best travel conditions in this month. See all of Argentina in December →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in San Juan in December
Warm but pleasant conditions in San Juan in December. Focus on lightweight, maybe with natural fabrics, cotton blend shirts, comfortable shorts, and breathable footwear. A light cover-up for sun protection is smart too. Wet weather is likely, so pack waterproof gear for multiple rainy days. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.What To Do in San Juan in December
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Argentina, check out our San Juan's climate page.
Temperature Rainfall Sunshine Humidity
See the full San Juan climate overview or explore weather in Argentina.
