September is the wettest month in the United States Virgin Islands with 5.6" (142mm) of rain. The conditions are hot and humid, although it rains for an average of 16 days in the month. The sunlight is oppressive due to the increase in the humidity, and it is imperative to wear sunscreen. The average temperatures are in the 78°F (25.6°C) to 90°F (32.2°C) range, with very few days above 95°F (35°C). The mountain slopes provide some respite from the heat but at the cost of frequent thunderstorms and rain. Wind speeds are mostly below 20mph (32.2km/h) except during storms. Have a look at the weather forecast before planning overnight camping trips. The wet season offers spectacular views of lush greenery amid waterfalls in the interior and the beautiful coasts from the mountain tops. September is usually a less popular month to visit the United States Virgin Islands.