Mary, I visited Maui at the end of November and thought it was the perfect weather (in the low 80s), but locals told me that Maui has a year-around temp avg between 75-85*F. So I would say anytime of the year would be a great time to visit Maui. Although if you are going to be outdoors all the time I would probably chose Dec-Mar as it is slightly cooler (& you might see the whales migrating!) The temperatures can vary based on where you are on the island too. If you plan on taking a tour of Haleakala take a sweatshirt as it can be around 40*F if you want to watch sunrise.