November is usually the wettest month of the year in Hawaii with an average rainfall of 4.9" (124mm). The average temperatures are in the mild 73°F (22.8°C) to 81°F (27.2°C) range with the Pacific High moving a little southward by the end of the summer. The effect of northeastern trade winds reduces to an extent, but the overall vast bodies of water surrounding the island ensure that there is minimal variation in temperatures. Coastal areas are dry, but mountain slopes see a substantial amount of rain in November. Mauna Kea Observatory registers an average temperature of 28°F (-2.2°C) to 45°F (7.2°C) with most of the nights during the winter below the freezing point. It is not a great idea to explore the mountains during the winter due to the rain, the increase in humidity and fog, as well as the presence of more sunny weather in the lowlands - Honolulu, averages 7 hours of average sunshine during November!