In terms of precipitation, rainfall in Vieques ranges from 1.3 - 5.2 inches per month. September is typically the wettest month, when rainfall can reach 5.2 in. February is typically the driest time to visit Vieques when rainfall is around 1.3 in.
If weather is an important factor for your trip to Vieques, use this chart to help with planning. For those seeking warmer temperatures, June is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 75.2 F).