In May, San Marcos typically sees daytime highs of 29.6°C and overnight lows around 17.6°C. Compared to the annual average high of 26.3°C, May runs +3.3°C.
May in San Marcos averages a daytime high of 29.6°C and an overnight low of 17.6°C.
May runs +3.3°C compared to San Marcos's annual average high of 26.3°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 29.6°C and cooler evenings around 17.6°C.