Quantico experience humid subtropical climate. Hence, expect shower throughout the year. Carrying raincoat or umbrella is definitely necessary when you are coming to Quantico. Having specific dry months is really difficult in this part of Virginia. However, to be specific, February is the only month that is considered dry. This is because, it receives the least amount of precipitation as compare to the other months. Hence, February can be considered as the best time to visit Quantico city. However, also learn about the climate for other months, so that you can pick an alternate option.