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July Weather in San Marcos, United States

Last updated: June 24, 2025

In July, the average temperature in San Marcos, United States hovers around 23°C (73°F). Expect the mercury to dip to a minimum of 15°C (60°F) while occasionally soaring up to a sizzling 40°C (105°F). With an average humidity level of 46%, the climate remains relatively comfortable. Rainfall is minimal, with an average precipitation of just 4 mm (0.2 in) spread across 0 days. Enjoy the warmth!

July Temperature in San Marcos

In July in San Marcos, the average temperature is 23°C (73°F). Maximums can reach 40°C (105°F), while minimums can drop to as low as 15°C (60°F). This makes San Marcos a great destination for travelers looking to enjoy warm weather with the possibility of cooler evenings.

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

The chart illustrates July 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, July typically has an average temperature of 23°C (73°F), with highs reaching up to 40°C (105°F) and lows dropping to around 15°C (60°F).
JanFebMarAprMayJunJulAugSepOctNovDec565657616368737573686356
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.

July Precipitation in San Marcos

In San Marcos in July, the precipitation amount is 4 mm (0.2 in) over the course of 0 days.

July Precipitation Trends in San Marcos

The chart displays monthly precipitation patterns in San Marcos, with values for each month alongside July’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how July’s conditions compare to those of other months. In San Marcos, July typically receives around 4 mm (0.2 inches) of precipitation spread over approximately 0 days.
JanFebMarAprMayJunJulAugSepOctNovDec70786832243415123570
Data source: Precipitation data for July generated using information from the Copernicus Climate Change Service.
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July Humidity in San Marcos

In San Marcos in July, humidity is 46%. With an average temperature of 23°C (73°F), this humidity feels like a warm, inviting embrace, making it pleasant for traveling as the air is comfortably moist without being too sticky or overwhelming.

July Average Humidity in San Marcos

This chart illustrates the average monthly humidity levels in San Marcos, with July’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In July, average humidity in San Marcos is approximately 46%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec72%77%67%56%46%48%46%42%52%58%66%74%
Data source: Humidity data for July generated using information from the Copernicus Climate Change Service.

July UV Index in San Marcos

In San Marcos in July, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in San Marcos.

Maximum UV Index Levels in San Marcos for July

The chart shows the monthly maximum UV Index (UVI) for San Marcos in July, 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 July, the maximum UV index in San Marcos typically reaches 11, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec469101112111010754
Data source: San Marcos July 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 July 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 July’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 July’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather13°C (56°F)70 mm (2.8 inches)72%moderate
February Weather13°C (56°F)78 mm (3.1 inches)77%high
March Weather14°C (58°F)68 mm (2.7 inches)67%very high
April Weather16°C (62°F)32 mm (1.3 inches)56%very high
May Weather17°C (63°F)24 mm (0.9 inches)46%extreme
June Weather20°C (68°F)3 mm (0.1 inches)48%extreme
July Weather23°C (73°F)4 mm (0.2 inches)46%extreme
August Weather24°C (75°F)1 mm (0.1 inches)42%very high
September Weather23°C (73°F)5 mm (0.2 inches)52%very high
October Weather20°C (69°F)12 mm (0.5 inches)58%high
November Weather17°C (63°F)34 mm (1.4 inches)66%moderate
December Weather14°C (57°F)70 mm (2.7 inches)74%moderate

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