In December, San Juan typically sees daytime highs of 28.8°C and overnight lows around 22.3°C. Compared to the annual average high of 30.4°C, December runs -1.7°C.
December in San Juan averages a daytime high of 28.8°C and an overnight low of 22.3°C.
December runs -1.7°C compared to San Juan's annual average high of 30.4°C, ranking #11 of 12 months by warmth.
Plan for daytime highs near 28.8°C and cooler evenings around 22.3°C.