Zanshin showed you an interesting chart, but you never know. There is always that odd storm. We were on St. John in NOVEMBER, for 'left handed Lenny" and had to be evacuated off, just ahead of the storm. We used to go to SXM or on cruises a LOT in September. We were actually on a cruise when Luis hit SXM. We were scheduled to go to the Eastern Caribbean, including SXM, and the ship instead went Western Caribbean. It was a very odd cruise, the sea was absolutely dead flat calm in the Western Caribbean. Now, living in Florida, I am more worried about something hitting our house here during hurricane season. I personally wouldn't be worried about going to SXM in September, if it weren't for living in Florida.
Hurricane prediction is a lot better now than it was years ago. If you go, just be very careful about watching the weather and make sure you buy trip insurance. It is a good time to go, for no crowds anywhere. Just know, as JD says, it's hotter during August and September.
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