Off season in BVI''''s
Spent 3 weeks in VI''s in July last year. Winds anything between 15-25kts. I was sailing an Island Packet so the high end of that scale suited us fine.
General weather.... We had a couple of heavy showers and a couple of cloudy days when a depression further south threatened to become a hurricane but overall it was hot and sunny with plenty of wind.
Beside lower cost, another advantage at that time of year is that you can always find somewhere to drop the hook.