In September, Haikou typically sees daytime highs of 22.9°C and overnight lows around 14.4°C. Compared to the annual average high of 20.9°C, September runs +2.0°C.
September in Haikou averages a daytime high of 22.9°C and an overnight low of 14.4°C.
September runs +2.0°C compared to Haikou's annual average high of 20.9°C, ranking #6 of 12 months by warmth.
Plan for daytime highs near 22.9°C and cooler evenings around 14.4°C.