Saba's climate is relatively consistent year-round — the trade winds keep temperatures comfortable at altitude and humidity is lower than on flatter Caribbean islands. The main tourist season runs December through April, when the weather is drier and seas calmer. This is the best time for diving, as visibility is at its highest and the Saba National Marine Park's rougher northern sites are most accessible.
May through November is the Atlantic hurricane season. Saba is not perfectly sheltered — the island has taken direct hits and its compact size makes evacuation difficult — but it sits slightly outside the main hurricane track and tends to see more tropical waves and heavy rain than direct storms. Diving remains good outside the peak of the season (August to October). The upside of the shoulder season is that the island is even quieter than usual and accommodation prices drop.
The best hiking conditions are December through March, when morning cloud cover is least likely to obscure the Mount Scenery summit. Whatever time of year you visit, mornings are always clearer than afternoons.