Rainfall averages 990 mm per year, with considerable seasonal variation. Generally, the wettest period is between September and November. The islands generally have low humidity and recurrent droughts. Hurricanes strike on average once a year. Temperatures average 27°C and range from 23°C in winter to 30°C in summer and autumn. The coolest period is between December and February. The low humidity makes it one of the most temperate climates in the world.