Weather in San Juan

Be prepared for any changes in temperature and precipitation in the city of San Juan. Here you will find an up-to-date weather summary, detailed charts, and forecasts for the near future to help you plan the perfect trip.

The climate of San Juan can be described as arid and temperate, with a large number of sunny days per year. Dry weather with very low rainfall levels is typical for this region of Argentina, making it an attractive destination for those who dislike prolonged rain. Due to its location in the foothills of the Andes, noticeable daily temperature fluctuations are observed here.

The city has distinct seasonality. Summer (from December to February) is warm here: average daytime temperatures reach 28°C, while nights remain comfortable and fresh. Winter (from June to August) is cool, especially at night when the thermometer can drop to 2-4°C, although during the day the air often warms up to a pleasant 15°C. The shoulder season is usually mild and favourable for walking.

A feature of the weather in San Juan is the almost complete absence of heavy downpours. Even in the summer months, when the highest number of wet days is recorded, the volume of precipitation remains minimal (about 2–3 mm). In winter, rain is a rarity. Tourists should take into account the dryness of the air and bring warm clothes for the evenings, regardless of the season.

The climate in San Juan is distinguished by pronounced seasonality, characteristic of this arid region of Argentina. The hottest period falls at the height of the southern summer — from December to February. In January, which is traditionally the warmest month, the average daytime temperature reaches 28.3°C. Summer weather here is sunny and dry, which makes it easier to tolerate high temperatures; however, travellers should remember the active sun during the daytime hours.

Winter, arriving in June and lasting until August, brings significant cooling. July is the coldest month of the year with an average temperature of about 8.2°C. During this period, nights become truly chilly: the thermometer drops on average to 1.6°C, so warm clothes in your luggage will be simply essential. At the same time, winter days often remain clear and dry, with daytime highs around 15°C, which is quite comfortable for walks under the sun.

An important feature of San Juan's temperature regime is the significant difference between day and night readings. Throughout the year, the temperature amplitude can be 10–13 degrees or more. Even after a hot summer day, the evening brings tangible freshness when the temperature drops to 17°C, and in winter the difference is felt even more acutely when a comfortable day is replaced by an almost frosty night. When planning your wardrobe for the trip, it is worth considering this "capriciousness" of the local weather and dressing in layers.

San Juan is characterised by an arid climate, typified by very low rainfall levels throughout the year. Even in the wettest periods, the amount of moisture falling remains minimal, measured literally in single units of millimetres. This makes the region attractive for travellers who prefer clear weather and wish to avoid prolonged downpours during their holiday.

Analysing annual statistics, one can highlight a conditional "rainy season", which falls on the summer months of the Southern Hemisphere — from December to February. January is the leader in precipitation frequency: on average, about 13 days with precipitation are recorded here, however, their total volume barely reaches 3 mm. This indicates that rains here are usually very weak, short-lived, or appear as light drizzle that does not create serious inconvenience for walks.

The winter period, especially from June to August, is considered the driest time of the year. In these months, the amount of precipitation tends towards zero (about 0 mm), and the number of days with any moisture decreases to 3–4 per month. Despite the fact that night temperatures in July can drop to +1.6°C, snowfall in the city is an exceptional phenomenon due to the lack of atmospheric moisture in the cold season.

When planning a trip to San Juan, it is important to consider the peculiarities of the local climate with its significant temperature changes. In summer, from December to February, when the air warms up on average to +28°C, you will need light clothing made of natural breathable fabrics, such as cotton and linen. Since the sun in this region of Argentina is very active, be sure to pack a wide-brimmed hat, quality sunglasses, and high SPF cream in your suitcase. Although statistics indicate the possibility of precipitation in summer, its volume is usually small, so instead of a heavy umbrella, it is better to take a compact raincoat.

The winter months (June–August) require more serious preparation: night temperatures can drop to +2°C, although during the day the air warms up to a comfortable +15°C. For this time of year, the principle of layering is ideal: a combination of a t-shirt, a warm sweater or fleece jacket, and a windproof jacket will allow you to quickly adapt to weather changes throughout the day. Warm clothing is also necessary for protection against winds, which can increase the feeling of coolness.

Regardless of the season, the main element of your wardrobe should be comfortable and durable walking shoes, especially if you plan excursions to natural attractions and rocky terrain. Given the often dry air, do not forget to bring moisturising cream and lip balm. A small backpack will become an indispensable accessory for carrying water, a windbreaker, and necessary small items during long walks around the city and its surroundings.