Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Flagstaff to Caribbean as you normally would.
In terms of precipitation, rainfall in Caribbean ranges from 2.2 - 6.1 inches per month. November is typically the wettest month, when rainfall can reach 6.1 in. February is typically the driest time to visit Caribbean when rainfall is around 2.2 in.
If weather is an important factor for your trip to Caribbean, 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 82.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 77.0 F).