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December Weather in San Marcos, Guatemala

Last updated: August 23, 2025

In San Marcos, Guatemala, the average temperature in December is a comfortable 15°C (59°F), with minimums dipping to 6°C (43°F) and maximums soaring to 22°C (72°F). Expect some rainy days, as precipitation totals around 38 mm (1.5 in) over 10 days. The air maintains a humidity level of 76%, adding a touch of moisture to the pleasant climate.

December Temperature in San Marcos

In December in San Marcos, the average temperature is 15°C (59°F). Maximums can reach 22°C (72°F) and minimums can be as low as 6°C (43°F). This weather makes it a perfect time for travelers to enjoy outdoor activities while packing layers for varying temperatures.

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

The chart illustrates December temperature patterns in San Marcos, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In San Marcos, December typically has an average temperature of 15°C (59°F), with highs reaching up to 22°C (72°F) and lows dropping to around 6°C (43°F).
JanFebMarAprMayJunJulAugSepOctNovDec585960616262616161616058
Data source: Temperature data for San Marcos 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 Marcos

In San Marcos in December, the precipitation amount is 38 mm (1.5 in) over the course of 10 days.

December Precipitation Trends in San Marcos

The chart displays monthly precipitation patterns in San Marcos, 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 Marcos, December typically receives around 38 mm (1.5 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec3129571243814532203594173268538
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in San Marcos

In San Marcos in December humidity is 76%. With an average temperature of 15°C (59°F), this humidity feels like a heavy blanket wrapping around you, making outdoor activities less enjoyable and often leading to a quick sense of fatigue while traveling.

December Average Humidity in San Marcos

This chart illustrates the average monthly humidity levels in San Marcos, 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 Marcos is approximately 76%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%68%59%57%65%66%75%82%82%83%80%76%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in San Marcos

In San Marcos in December, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in San Marcos.

Maximum UV Index Levels in San Marcos for December

The chart shows the monthly maximum UV Index (UVI) for San Marcos 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 Marcos typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec121416161515161514141110
Data source: San Marcos 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.

How December Weather in San Marcos Compares to Other Months

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

This table compares monthly weather conditions in San Marcos, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather14°C (58°F)31 mm (1.2 inches)76%extreme
February Weather15°C (59°F)29 mm (1.1 inches)68%extreme
March Weather16°C (61°F)57 mm (2.2 inches)59%extreme
April Weather16°C (62°F)124 mm (4.9 inches)57%extreme
May Weather17°C (63°F)381 mm (15.0 inches)65%extreme
June Weather16°C (62°F)453 mm (17.8 inches)66%extreme
July Weather16°C (62°F)220 mm (8.7 inches)75%extreme
August Weather16°C (62°F)358 mm (14.1 inches)82%extreme
September Weather16°C (61°F)417 mm (16.4 inches)82%extreme
October Weather16°C (61°F)326 mm (12.8 inches)83%extreme
November Weather16°C (60°F)85 mm (3.4 inches)80%extreme
December Weather15°C (59°F)38 mm (1.5 inches)76%very high

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