In May, San Marcos typically sees daytime highs of 22.5°C and overnight lows around 10.9°C. Compared to the annual average high of 23.0°C, May runs -0.5°C.
May in San Marcos averages a daytime high of 22.5°C and an overnight low of 10.9°C.
May runs -0.5°C compared to San Marcos's annual average high of 23.0°C, ranking #6 of 12 months by warmth.
Plan for daytime highs near 22.5°C and cooler evenings around 10.9°C.