Hawaii's climate is defined by the dry season in summer and the rainy season from November to March. It's likely to rain somewhere in the islands every day, but showers seldom last long. Temperatures year-round consistently average from 80 to 89 degrees during the day and 65 to 75 degrees at night. However, if you head for the mountains, the temperatures drop the higher you go. Hurricanes and tsunamis aren't unheard of, but they are extremely rare.