That question can be answered in different ways but i'll assume you're after this.
If you go peak or high which tends to be around December to April then you can expect the weather to be warmer and drier. Off peak seasons are still warm, but it may be overcast and rain a bit more.
I visited in June and it was over 25c everyday and it only rained and night time. Of course during peak season there will be a lot more people and the prices will be higher at the Maldives resorts http://www.maldivesresortdeals.com.
If you are after affordability and want to avoid the bulk of the travelers go off peak. There are also peak seasons for marine life and surfing which the Maldives is also known for. about 3 years ago