In May, Harlingen typically sees daytime highs of 31.4°C and overnight lows around 21.6°C. Compared to the annual average high of 28.5°C, May runs +2.8°C.
May in Harlingen averages a daytime high of 31.4°C and an overnight low of 21.6°C.
May runs +2.8°C compared to Harlingen's annual average high of 28.5°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 31.4°C and cooler evenings around 21.6°C.