St Lucia weather is tropical, with temperatures varying from an average low of 76 - 81 F and an average high of 82 - 86 F through out the year. The weather in St Lucia basically comprise of two patterns. They are the dry season and rainy season.
The dry season runs from December to May but that does not mean that there is no rain. On the contrary, you will find that it still rains at that time of the year. The climate in St Lucia at that time of the year is normally dry but it is moderated by the northeastern trade winds.
Most visitors come to St Lucia that time of the year to frolic in the sun on one of its lovely beaches. Having less rain fall is probably a good reason why they come around that time because they vacation remains uninterrupted by heavy rains or the possibility of a tropical storm.
The rainy season is not all rain as the name suggests but more rain is expected during that time because of all the climate changes that happen on the African coast, hence the term rainy season.
It would be good to note that there have not been any hurricanes in St Lucia since hurricane Allan in 1980, but during the rainy season it is more likely to be affected by one.
You should get up to date information on the weather in St Lucia before you decide to come to St Lucia. It is best if you do so a week in advance and just before you are about to leave to come here.