San Juan Temperature by Month

The average annual maximum temperature in San Juan, San Juan Province, Argentina is 26°C (79°F), with daytime highs ranging from 18°C (64°F) in July to 33°C (91°F) in January. This page covers monthly averages, day-night differences, and how San Juan compares to cities worldwide.

Depending on the time of the year, temperatures range from very warm to mild in San Juan. At night, minimum temperatures range from 19°C (66°F) in January to 2°C (36°F) in July.

The chart below illustrates the average maximum day and minimum night temperatures in San Juan by month:

Low temperatures are most often recorded between 4 AM and 6 AM, while highs typically occur around 3 PM. January, the city's warmest month, sees 338 hours of sunshine.

The chart below shows the average temperature throughout the year:

San Juan's average annual maximum temperature is 26°C (79°F). To put that in context, here's how it compares to a few well-known destinations:

Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.

Queenstown, New Zealand averages 10°C (50°F) annually, remember seasons are flipped, so its coldest months fall in June and July.

New York City, USA averages 17°C (63°F) a year, with hot humid summers and cold winters that bring regular snowfall.

Melbourne, Australia averages 20°C (68°F) annually, known for unpredictable weather, with four seasons sometimes happening in one day.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In San Juan, July is the coolest month, with average highs of 18°C (64°F) and humidity around 57%, considered moderate. In January, the warmest month, temperatures average 33°C (91°F) with 44% humidity, conditions that feel moderate. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Whether a city sits on the coast or deep inland makes a significant difference to its climate. Coastal areas tend to have more stable temperatures year-round, large bodies of water absorb heat slowly in summer and release it gradually in winter, keeping extremes in check. Cities far from the sea don't benefit from that buffer, which is why continental climates tend to have hotter summers and colder winters than their coastal counterparts at the same latitude.

For more on San Juan's weather, including monthly rainfall, sunshine hours, and humidity, visit our San Juan climate page.