December Weather in San Martin, Argentina

Last updated: August 21, 2025

In San Martin, Argentina, December brings a dynamic shift in weather, characterized by maximum temperatures soaring up to 42°C (108°F) and an average of 26°C (80°F). With nighttime lows dipping to 12°C (54°F), the month showcases a notable range in diurnal temperature variation. While the region experiences an overall low humidity level of 35%, precipitation is modest, with an average of 24 mm (1.0 in) spread across five rain days. This blend of warmth and occasional rainfall creates a vibrant atmosphere, perfect for outdoor summer activities.

December Temperature in San Martin

In San Martin, Argentina, December ushers in the peak of summer, bringing with it pleasantly warm temperatures that invite outdoor adventures. The month starts with minimums around 12°C (54°F), providing a comfortable atmosphere for early risers, while average highs climb to a sizzling 42°C (108°F), promising sun-soaked days. This trend mirrors the gradual increase from previous months, showcasing a steady rise in warmth that heightens into January's peak. As the temperatures shift from the mild 9°C (48°F) in November to the more tropical ambiance in December, locals and visitors alike revel in the opportunities for hiking, swimming, and savoring the vibrant landscapes that flourish under the summer sun.

December Weather in San Martin: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in San Martin, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Martin, December typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec817773655548475361687579
Data source: Temperature data for San Martin generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in San Martin

December in San Martin, Argentina, wraps up the year with a modest precipitation total of 24 mm (1.0 in), falling within a consistent pattern observed throughout the months. This month typically experiences rainfall on about five days, maintaining a stable rhythm similar to November, which recorded 27 mm (1.1 in) across five rainy days. Notably, December's precipitation is an increase from the drier winter months of June and July, when only 5 mm and 4 mm were recorded, respectively. As the year draws to a close, this uptick in rain supports the region's transition into the warmer summer season, providing a refreshing end to the year while hinting at the wetter months to come.

December Precipitation Trends in San Martin

The chart displays monthly precipitation patterns in San Martin, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In San Martin, December typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec36402620175426132725
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in San Martin

In the heart of summer, December in San Martin, Argentina, brings a refreshing drop in humidity to just 35%, the lowest point of the year. This shift marks a significant decline from the preceding months, where humidity consistently peaked in the autumn at 69% in May and hovered around 65% through the mid-year. As the year winds down, the transition to summer provides a crisp contrast, showcasing a trend of decreasing humidity that sets the stage for the warmer days ahead. Enjoy the pleasant and airy ambiance of December, perfect for outdoor activities in this beautiful region.

December Average Humidity in San Martin

This chart illustrates the average monthly humidity levels in San Martin, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in San Martin is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec40%46%54%65%69%64%65%60%51%49%44%36%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in San Martin

In December, San Martin, Argentina, experiences an extreme UV Index of 15, which marks a continuation of the high levels seen throughout the late spring and early summer months. This pattern is consistent with the previous months, where both January and February also faced severe UV levels at 15 and 14, respectively. Interestingly, as the calendar transitions from March to April, there's a noticeable dip, with the UV Index dropping to 8, indicating a temporary relief before it rises again in the peak months. The quick return to extreme levels in October and November reinforces the importance of sun safety, as the burn time remains critically low at just 10 minutes during these months. To stay informed and prepared, check out the detailed insights on the San Martin UV Index.

Maximum UV Index Levels in San Martin for December

The chart shows the monthly maximum UV Index (UVI) for San Martin in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In December, the maximum UV index in San Martin typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec151412864468121415
Data source: San Martin December UVI data generated using information from the Copernicus Climate Change Service.

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.

December Sunshine in San Martin

December in San Martin, Argentina, shines brightly with an impressive 391 hours of sunshine, marking it as the sunniest month of the year. This radiant finale to the year follows a steady increase in daylight hours, starting from 267 hours in May and steadily climbing to a peak in December. Notably, December’s sunshine not only surpasses the cooler months but also reflects a joyous transition from spring into summer, where the days stretch longer and warmer. As daylight hours increase, San Martin transforms into a vibrant hub for outdoor activities, making it an ideal destination for those seeking both adventure and relaxation under the Argentinian sun.

Monthly Sunshine Duration in San Martin: December Highlighted

The December sunshine duration represents the total number of hours San Martin experiences direct sunlight during the month of December, excluding cloudy or obstructed periods. This chart compares the sunshine duration of December with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec311h324h327h276h267h263h279h314h321h354h369h391h
Data source: San Martin December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in San Martin During December

In December, San Martin, Argentina, enjoys a 67% chance of sunny weather, marking a slight dip from the preceding months but still promising plenty of bright days. Compared to the peak sunshine of July and August, where chances soar above 80%, December transitions into the warmer summer months, reflecting the changing climate. Despite this decrease, it remains relatively high among the year’s averages, as the previous months of November and October highlight consistently favorable forecasts with probabilities around 76% and 79%. As summer approaches, locals and visitors alike can look forward to enjoyable weather, making December a delightful time to soak up the sun in this picturesque region.

Percentage of Sunny Days in December in San Martin

The chart illustrates the percentage of sunny days in San Martin throughout the year, with December highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often San Martin experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec71%65%60%74%66%64%87%81%83%79%76%67%
Data source: San Martin December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in San Martin in December

In San Martin, Argentina, the pattern of daylight duration throughout the year reveals a beautiful ebb and flow. The year begins with 14 hours of sunlight in January, a peak that gently tapers to 12 hours by March, heralding the arrival of autumn. As the days shorten further, April and May see a reduction to 11 and 10 hours, respectively, culminating in the winter months of June, where daylight dips to its lowest at 9 hours. Interestingly, July and August bounce back, providing 10 hours once again. As spring returns, daylight begins to lengthen, re-establishing 11 hours in September and gradually increasing to 14 hours by December, wrapping up the year with vibrant summer days, full of light and warmth. This rhythmic cycle not only enhances the natural beauty of the region but also serves as a reminder of the changing seasons and the passage of time.

Average Daylight Hours in San Martin for December

The chart illustrates the variation in daylight duration in San Martin throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec14h 2m13h 14m12h 14m11h 13m10h 23m9h 59m10h 12m10h 56m11h 54m12h 55m13h 49m14h 17m
Data source: San Martin daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in San Martin

In December, the winds of San Martin, Argentina, pick up a lively pace, averaging 3.5 m/s (8 mph), which ties the late spring's breezy charm. This increase follows a series of gentle winds throughout the year, peaking in both October and September at similar speeds. Notably, the transition from the quieter months of winter, where gusts linger around 2.3 to 2.4 m/s (5 mph), to the early summer's delightful breezes suggests a welcoming shift. The consistent 3.5 m/s winds in December, coupled with the region's stunning landscapes, create an invigorating atmosphere that sets the stage for outdoor adventures and exploration. As the year winds down, December not only brings a refreshing breeze but also a promise of warmth and activity in this picturesque Argentinian locale.

Average December Wind Speed in San Martin

The chart displays monthly wind speed patterns in San Martin, with values for each month shown alongside December's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how December's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.42.62.82.42.42.32.42.83.53.63.33.5 m/s
Data source: San Martin December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in San Martin Compares to Other Months

Weather in San Martin varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in San Martin, focusing on differences in temperature, rainfall, humidity, and UV levels.

In December, the weather is characterized by warm temperatures, with a minimum of 12°C (54°F) and an average of 26°C (80°F), reaching a maximum of 42°C (108°F). Precipitation is relatively low, at 24 mm (1.0 in) over about 5 days, and humidity sits at 35%. In contrast, January experiences slightly cooler conditions, with a minimum of 10°C (49°F) and an average of 27°C (82°F), while still peaking at 42°C (107°F). The month sees increased rainfall, totaling 36 mm (1.4 in) over 6 days, and humidity rises to 40%. For more detailed information, you can check the San Martin weather in January.

December and February present similar warm weather patterns, although there are some key differences worth noting. In December, temperatures range from a minimum of 12°C (54°F) to a maximum of 42°C (108°F), with an average temperature of 26°C (80°F) and relatively low humidity at 35%. Conversely, February sees a slight increase in minimum temperature to 13°C (55°F) and a drop in average temperature to 25°C (78°F), with a maximum temperature of 41°C (107°F). February also experiences more precipitation, totaling 39 mm (1.6 in) over 7 days, compared to December’s 24 mm (1.0 in) over 5 days and higher humidity levels at 46%. For more details, you can check out San Martin weather in February.

In December, the weather is characterized by higher temperatures, with minimums around 12°C (54°F) and maximums soaring to 42°C (108°F), making it quite warm overall, with an average temperature of 26°C (80°F). Humidity levels are relatively low at 35%, and there's minimal precipitation of 24 mm (1.0 in) spread over 5 days. In contrast, March experiences slightly cooler temperatures, with minimums dropping to 7°C (44°F) and maximums reaching up to 38°C (101°F). The average temperature is 23°C (73°F), and humidity increases to 54%, providing a more humid atmosphere. Rainfall is slightly higher in March, with a total of 26 mm (1.0 in) over the same number of days. For more insights, check out San Martin weather in March.

December and April present contrasting weather patterns. In December, temperatures range from a minimum of 12°C (54°F) to a scorching maximum of 42°C (108°F), with an average of 26°C (80°F). The month experiences 24 mm (1.0 in) of precipitation over about five days, accompanied by relatively low humidity at 35%. In stark contrast, April sees cooler temperatures, with a minimum of 2°C (36°F) and a maximum of 34°C (93°F), averaging 18°C (66°F). The precipitation in April is slightly lower at 20 mm (0.8 in) but occurs over fewer days—just three—with higher humidity levels reaching 65%. For a deeper dive into the weather conditions during this time, check out San Martin weather in April.

December features significantly warmer temperatures compared to May, with average highs reaching a scorching 42°C (108°F) and lows around 12°C (54°F). In contrast, May sees much cooler temperatures, with a maximum of 27°C (81°F) and a minimum dropping to 0°C (32°F). Precipitation levels are slightly higher in December at 24 mm (1.0 in) over 5 days, while May experiences a drier spell with just 17 mm (0.7 in) on 2 days. Additionally, the humidity in May is notably higher at 69%, compared to a drier 35% in December. For more details on the weather in May, you can check San Martin weather in May.

In December, the weather is characterized by high temperatures, with a minimum of 12°C (54°F) and a scorching maximum of 42°C (108°F), creating an average of around 26°C (80°F). This month experiences relatively low precipitation of 24 mm (1.0 in) over five days and humidity levels at 35%, contributing to a dry heat. In contrast, June brings cooler temperatures, where the minimum dips to -4°C (26°F) and the average is a mere 9°C (48°F), with a maximum reaching 26°C (79°F). The month has significantly less rainfall at just 5 mm (0.2 in) over a single day and higher humidity at 64%. For more details on June weather, you can check San Martin weather in June.

The weather in December contrasts sharply with that of July. In December, temperatures soar, with a minimum of 12°C (54°F) and a maximum reaching up to 42°C (108°F), creating a warm average of 26°C (80°F). This month also sees relatively low precipitation at 24 mm (1.0 in) over approximately five days and a humidity level of 35%. In stark contrast, July brings much cooler conditions, with temperatures ranging from a chilly -3°C (27°F) at night to a high of 23°C (74°F), averaging around 8°C (47°F). Rain is minimal, with only 4 mm (0.2 in) falling over just one day, while the humidity is notably higher at 65%. For more details, check out San Martin weather in July.

The weather in December is characterized by warmer temperatures, with averages reaching up to 26°C (80°F) and maximums soaring as high as 42°C (108°F). In contrast, August experiences much cooler conditions, with average temperatures around 12°C (54°F) and a maximum of 32°C (90°F). Additionally, December has a low level of precipitation at 24 mm (1.0 in) over five days, while August remains notably drier with only 2 mm (0.1 in) and no days of rainfall. Humidity levels also differ significantly, with December being drier at 35% compared to August's higher 60% humidity. For those interested in more about this month, you can check San Martin weather in August.

December and September present contrasting weather conditions. In December, temperatures range from a minimum of 12°C (54°F) to a scorching maximum of 42°C (108°F), with an average of 26°C (80°F). The month typically experiences low humidity at 35% and receives about 24 mm (1.0 in) of rain over five days. In contrast, September is much cooler, with temperatures dipping to a minimum of -1°C (31°F) and reaching a maximum of 36°C (97°F), averaging around 16°C (62°F). The humidity is higher at 51%, but it sees significantly less precipitation, with only 6 mm (0.2 in) over just one day. For more details on September weather conditions, check out San Martin weather in September.

December and October present a stark contrast in weather conditions. In December, temperatures soar with a minimum of 12°C (54°F) and an average of 26°C (80°F), peaking at a scorching 42°C (108°F). The month is relatively dry, with only 24 mm (1.0 in) of precipitation over 5 days and a humidity level of 35%. In comparison, October experiences cooler temperatures, with a minimum of 2°C (35°F), an average of 20°C (68°F), and a maximum of 39°C (103°F). Precipitation is lower at 13 mm (0.5 in) over just 3 days, but the humidity is higher at 49%. For more details on October's weather, you can check San Martin weather in October.

In comparing the weather between November and December, December tends to be warmer overall, with average temperatures rising from 24°C (75°F) in November to 26°C (80°F). The minimum temperature also increases to 12°C (54°F) in December from 9°C (48°F) in November, while the maximum temperature reaches a high of 42°C (108°F), slightly above November's peak of 40°C (105°F). Rainfall remains fairly consistent, with December receiving 24 mm (1.0 in) compared to November's 27 mm (1.1 in), both spread out over five days. However, December's humidity drops to 35%, compared to November's higher 44%, indicating a drier feel in the air as the year wraps up. For more details, check out San Martin weather in November.

Compare San Martin's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in San Martin

As December rolls into San Martin, the weather truly showcases the region's vibrant summer vibe. Temperatures soar, reaching their peak while offering a pleasant average that invites outdoor adventures. Unlike the cooler months, December experiences only a few days of light precipitation, allowing the landscape to bask in plenty of sunshine. The relatively low humidity further enhances the warmth, making it an ideal time for those who enjoy the sweltering summer heat. For a deeper understanding of the dramatic seasonal shifts, explore the full San Martin Climate details.