San Juan Weather in January
January in San Juan averages 33°C (91°F) during the day and 19°C (66°F) at night. Around 37 mm (1.5 in) of rainfall is typical for this time of year.
Rainfall in San Juan in January
Historically, January sees about 5 days of rain, with a monthly average of 37 mm (1.5 in). The rain this month typically falls in concentrated bursts rather than all-day showers. Expect a few heavier spells rather than constant grey skies.
Temperature in San Juan in January
In January, expect very high temperatures in San Juan, with highs of 33°C (91°F) and lows of 19°C (66°F) at night. For most visitors, the main thing to prepare for is the heat during the day. Nights drop to around 19°C (66°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable. While these temperatures are averages, expect some days to be hotter. Choose light, airy clothing to handle the warmth effectively.
Sunshine in San Juan in January
Enjoy a sunny month with about 338 hours of sunshine, the clear skies make San Juan even more beautiful.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 January
Min Temperature
19°C (66°F)
Max Temperature
33°C (91°F)
Chance of Rain
16%
Precipitation
37 mm (1.5 in)
Rainy days
5 days
Humidity
44%
Sunshine
338 hours
Percentage Sunshine
78%
Daily Historical Temperatures
51-year average (1976-2026)
Based on our historical records, temperatures in San Juan typically stay consistent throughout January, with daily highs averaging around 33°C (91°F). Nights are pleasant, with lows around 20°C (68°F).
Average temperatures in January
Historical weather for San Juan in January
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 January
Based on 49 years of weather observations (1976-2025), these are the most extreme conditions recorded in San Juan.
- On January 30, 2003, temperatures climbed to 45°C (113°F), marking the warmest January day on record.
- San Juan registered its coldest January night on January 18, 2019, with temperatures dropping to 10°C (50°F).
Best Places in Argentina in January
Find out more about the weather in Argentina and which places have the best travel conditions in this month. See all of Argentina in January →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in San Juan in January
Pack for serious heat in San Juan in January. Prioritize clothing that breathes and doesn't cling or stick. Lightweight cotton, linen, and moisture-wicking fabrics are ideal. A wide hat provides welcome shade. Light rain is possible, so consider bringing a small umbrella or rain jacket. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.What To Do in San Juan in January
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.
