The rainy season in Curacao starts in October and ends in January. During this period, there’s an average of 100 millimeters of rain per month; significantly more than during the rest of the year, but too little to speak of a real rainy season. So the rainy season should not be an issue when visiting Curacao during this period.
Days full of continuous rain are very rare in Curacao. Rainfall is usually heavy but short. Miraculously, these downpours are mostly at night and in the morning. The showers are usually very local and soon blow over again. This makes it somewhat difficult to make an accurate weather forecast.