Saipan is a tropical island with warm weather all year. The average temperature is consistently about 85 degrees Farenheit. The island experiences occasional rain showers during the rainy season, which is from about May to November. There are usually plenty of sunny days during these months as well, however. The rest of the year is mostly dry, with strong trade winds. Additionally, the air is clean relative to other, more industrialized parts of the world due to the lack of pollution. Check current weather conditions.