San Juan Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit San Juan.
Climate overview of San Juan
Temperatures in San Juan, San Juan Province, Argentina, vary greatly throughout the year. January is the hottest month at 33°C (91°F), while July is the coldest at 18°C (64°F).
The city tends toward dry conditions, with around 324 mm (13 in) of rain/snowfall per year. It does, however, have very little rainfall for most of the year, with very warm summers and mild winters. December is the sunniest month, averaging 11.7 hours of sunshine per day.
San Juan Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in San Juan - and find the best time to visit.
Monthly Temperature in San Juan
The climate in San Juan is known for significant temperature differences throughout the year, making the weather dynamic. Typically, average maximum daytime temperatures range from a very warm 33°C (91°F) in January to a moderate 18°C (64°F) in the coolest month, July.
Nights vary from 19°C (66°F) in January to around 2°C (36°F) during the colder months.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in San Juan
San Juan has a relatively dry climate with low precipitation, averaging 324 mm (13 in) of rain/snowfall annually. The climate in San Juan shows significant variation throughout the year. Expect moderate rainfall in December, the wettest month, with an average of 40 mm (1.6 in) of precipitation over 4 rainy days.
In contrast, the driest month June offers drier and sunnier days, with around 12 mm (0.5 in) of rainfall over a single rainy day. For more details, please visit our San Juan Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in San Juan
For those who appreciate different seasons, San Juan serves as an ideal destination. Expect longer, more sun-filled days in December with an average of 11.7 hours of sunshine daily, and embrace the darker days in June, offering only 6.9 hours of daily sunlight.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in San Juan by Month
The relative humidity is moderate throughout the year in San Juan.
The city experiences its highest humidity in June, reaching 63%. In October, the humidity drops to its lowest level at 38%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit San Juan
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: March, April, May, June, July, August, September and October
- Warmest weather: January, February and December
- Most sunshine: January and December
- Seasonal pattern: Very little rainfall for most of the year, with very warm summers and mild winters
Frequently asked questions about the climate in San Juan
What is the best time to visit San Juan?
March, April, May, June, July, August, September and October typically offer the most optimal weather in San Juan. In contrast, January tends to have less optimal conditions. San Juan has very little rainfall for most of the year, with very warm summers and mild winters.
What temperatures can I expect in San Juan?
Daytime highs range from 18°C (64°F) in July to 33°C (91°F) in January. Nighttime lows range from 2°C (36°F) to 19°C (66°F). Temperatures vary considerably through the year.
How much rain does San Juan get?
Annual rainfall is around 324 mm (13 in). December is the wettest month with 40 mm (1.6 in), while June is the driest with 12 mm (0.5 in).
How sunny is San Juan?
San Juan receives around 3,365 hours of sunshine per year. December is the sunniest month with 350 hours, while June is the cloudiest with just 208 hours. Overall, San Juan enjoys abundant sunshine.
San Juan 3-Day Forecast
San Juan on the map
San Juan is highlighted - select any city to see its climate.
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