In December, Oceanside typically sees daytime highs of 18.6°C and overnight lows around 8.0°C. Compared to the annual average high of 21.2°C, December runs -2.6°C.
December in Oceanside averages a daytime high of 18.6°C and an overnight low of 8.0°C.
December runs -2.6°C compared to Oceanside's annual average high of 21.2°C, ranking #9 of 12 months by warmth.
Plan for daytime highs near 18.6°C and cooler evenings around 8.0°C.