San Juan Climate

Last updated: January 18, 2025

San Juan, Argentina, is characterized by a Köppen-Geiger climate classification of BWk (Cold desert) and BWh (Hot desert), showcasing a remarkable temperature range throughout the year. The region experiences minimum temperatures plummeting to -16°C (4°F) in July, paired with a sizzling maximum of 43°C (110°F) in December. With an average annual temperature of 16°C (62°F), San Juan exemplifies the extreme conditions typical of desert climates, highlighting the stark contrasts that define its weather patterns.

San Juan temperature by month

San Juan, Argentina, exhibits distinct seasonal temperature patterns characterized by harsh winters and scorching summers. January and February mark the height of summer, with average temperatures around 25°C (76°F) and 23°C (73°F), respectively, while maximums soar to 42°C (108°F) and 41°C (106°F). As autumn approaches in March and April, temperatures begin to decline, highlighted by average readings of 20°C (69°F) and 17°C (62°F), with noticeable drops in nighttime lows. The colder months from May through July present a stark contrast, showcasing minimum temperatures dipping to -16°C (4°F) in July, alongside average highs around 26°C (80°F). Spring emerges in August, gradually bringing warmer averages, culminating in December when temperatures rebound with highs reaching 43°C (110°F), completing the cyclical nature of this desert climate.

Monthly Temperatures in San Juan, Argentina

The chart illustrates San Juan's temperature patterns throughout the year, with values aggregated from various locations across the region. It highlights seasonal variations and temperature changes across the months.
JanFebMarAprMayJunJulAugSepOctNovDec767369625346455157637073
Data source: San Juan temperature data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.
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The average of daily temperatures (24 hours) calculated across all days in the month.

Nueve de Julio experiences a significant temperature range, with minimum temperatures dipping to -5°C (24°F) in June and peaking at 42°C (109°F) in December monthly temperatures in Nueve de Julio. In contrast, Tamberias sees even colder winters, with minimums falling to -13°C (9°F) in July, while its summers reach a maximum of 33°C (91°F) in January monthly temperatures in Tamberias.

Precipitation Patterns in San Juan

San Juan, Argentina, showcases a highly variable precipitation pattern throughout the year, with most rainfall concentrated in the summer months. January and February typically experience the highest levels of precipitation, each receiving approximately 47 mm (1.9 in) and 47 mm (1.8 in), accompanied by an average of six rainy days. This seasonal rainfall begins to taper off in the following months, with March and April showing a decrease to 37 mm (1.4 in) and 26 mm (1.0 in), respectively, resulting in fewer rainy days, indicating a transition towards dry conditions.

As the year progresses into winter and early spring, precipitation diminishes significantly, reaching its lowest point in August with a mere 5 mm (0.2 in) and no recorded rainy days. The trend of limited rainfall continues into June and July with totals of 11 mm (0.5 in) and 12 mm (0.5 in), respectively. However, precipitation levels begin to rise again in October and November, with values of 27 mm (1.1 in) and 33 mm (1.3 in), which leads into December's increase of 43 mm (1.7 in), illustrating the typical cyclical nature of seasonal rainfall trends in this arid desert climate.

Monthly Average Precipitation in San Juan, Argentina

The average monthly precipitation in San Juan, providing insights into seasonal rainfall patterns and the region's precipitation trends throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec47473727211212518273343
Data source: San Juan precipitation data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.
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Sunshine Duration in San Juan

San Juan, Argentina, basks in abundant sunshine throughout the year, with a pronounced seasonal variation that emphasizes its arid climate. The months from January to March showcase the peak sunshine duration, with January receiving 313 hours, rising to 327 hours in February and peaking at 342 hours in March. This notable increase signifies the transition into summer, during which residents and visitors alike can fully enjoy the warm, sun-drenched days. Following this sunny trio, April witnesses a slight decrease to 296 hours, hinting at the approaching winter when daylight hours become shorter.

As the seasons shift into the cooler months, sunshine duration remains relatively high despite a gradual decline, with May at 282 hours and June at 277 hours. The trend begins to trend upwards again, culminating in October with 358 hours and reaching 394 hours in December. The final months of the year illustrate the return to robust sunshine, contrasting starkly with the winter fluctuations. Overall, San Juan enjoys a remarkable abundance of sunshine, making it a delightful destination for those seeking warmth and light throughout the majority of the year.

Monthly Sunshine in San Juan, Argentina

Monthly sunshine duration represents the total hours of direct sunlight San Juan receives each month, excluding periods when the sun is obscured by clouds or other obstructions.
JanFebMarAprMayJunJulAugSepOctNovDec313h327h342h296h282h277h292h319h329h358h375h394h
Data source: San Juan sunshine duration data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.

San Juan UV Index Trends

San Juan, Argentina, experiences notably high UV Index levels, particularly during the summer months when protective measures against solar exposure are essential. The UV Index peaks at 17 in January and December, categorized as extreme, meaning unprotected skin can burn in just 10 minutes. Similarly, February and March follow closely with indices of 16 and 14, respectively, maintaining the extreme exposure category. As the sun shines intensely during these months, awareness and precautions become paramount for residents and visitors alike, especially when engaging in outdoor activities.

As autumn approaches, the UV Index begins to decline, with April transitioning to a 10 which is categorized as very high, allowing for a slightly increased burn time of 15 minutes. By May and June, the index settles to values of 7 and 6, classified as high, with burn times extending to 25 minutes. This trend continues into the mid-year months, peaking again in August at 9, returning to a very high exposure level. Overall, while San Juan enjoys generous sunshine, the accompanying UV Index highlights the importance of sun safety, especially during peak periods to mitigate the risk of skin damage.

Monthly Maximum UV Index for San Juan, Argentina

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in San Juan. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec17161410767912151617
Data source: San Juan UV Index data aggregated from multiple regional locations, generated using Copernicus Climate Change Service information.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

Daylight Hours in San Juan

In San Juan, Argentina, daylight duration varies significantly throughout the year, reflecting the region's distinct seasonal transitions. During the summer months, January and February offer a generous 13 hours of daylight, allowing ample time for outdoor activities and enjoyment of the warm climate. This trend continues into March, where daylight begins to wane slightly to 12 hours. As autumn sets in during April, daylight further decreases to 11 hours, signaling the gradual shift towards shorter days.

By the time winter arrives in May, daylight shrinks to 10 hours, a trend that persists through June and July. However, as spring approaches in August, daylight duration begins to increase once more, returning to 11 hours. This upward trend culminates in December as San Juan sees the longest day of the year at 14 hours, highlighting the seasonal rhythm of sunlight that captivates residents and visitors. Overall, this variation in daylight provides a dynamic backdrop to the climate, enhancing the region's unique character.

Average Monthly Daylight Hours in San Juan, Argentina

This chart shows the total daylight hours San Juan receives each month, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec833h789h733h676h629h606h619h660h714h771h821h847h
Data source: San Juan daylight hours, calculated based on aggregated data for various regional locations, determined by the times between sunrise and sunset.

Climate Highlights of San Juan's Popular Destinations

Nueve de Julio, Argentina experiences a diverse climate throughout the year, with hot summers and cold winters. January and February boast high temperatures averaging around 27°C (81°F) to 25°C (78°F) and significant sunshine, with January receiving up to 310 hours. In contrast, the winter months of June and July can be chilly, with average temperatures dropping to 9°C (48°F) and 8°C (47°F), respectively. Rainfall is generally low, peaking in December (27 mm) and January (26 mm), while sunshine hours are highest in the late spring and summer months. For more detailed information, visit Nueve de Julio climate.

Tamberias, Argentina experiences a diverse climate, with summer temperatures peaking in January at a maximum of 33°C (91°F) and winter lows reaching -13°C (9°F) in July. Annual precipitation is relatively moderate, with January receiving the most at 31 mm (1.2 in), and August being quite dry with only 8 mm (0.3 in). The area enjoys plentiful sunshine, particularly in December, which boasts 412 hours. For more detailed information, visit Tamberias climate.

Conclusion

In conclusion, San Juan, Argentina, presents a fascinating climate characterized by its extreme temperatures, abundant sunshine, high UV Index, and varying daylight duration throughout the year. The stark seasonal transitions—from the scorching heat of summer with peak UV levels to the milder winter months with shorter days—demonstrate the unique attributes of this arid desert region. Understanding these climatic nuances is essential for residents and visitors alike, as they navigate outdoor activities and sun exposure in a landscape defined by its vibrant sunlight and the rhythm of its distinct seasons. Overall, San Juan emerges as a compelling destination for those seeking to experience the remarkable interplay between climate and lifestyle in a sun-drenched environment.

Discover the Climate of San Juan's Places

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