Direct answer
Either can be wonderful, but choose Hawaii if you want iconic scenery, reliable tourism infrastructure, and a more developed honeymoon experience; choose St. Vincent if you want a quieter, less-touristed Caribbean vibe, lower crowds and potentially lower cost—but accept smaller-scale infrastructure and higher hurricane-season risk.
Why choose Hawaii
- Scenery & variety: Volcanoes, waterfalls, black-sand beaches, lush valleys and dramatic coastlines across islands (Oahu, Maui, Kauai, Big Island). Great for unforgettable photo ops.
- Infrastructure & convenience: Wide range of luxury resorts, honeymoon packages, rental cars, dependable guided tours, good medical and tourist services.
- Activities: Helicopter tours, sunset sails, luaus, snorkeling with clear water, great hiking and whale-watching (seasonal), spa and fine-dining options.
- Predictability: Late September is shoulder season—fewer crowds than summer, still good weather with warm water; lower (but not zero) chance of storms compared with peak hurricane months.
Why choose St. Vincent (and the Grenadines)
- Intimate, off-the-beaten-path feel: Smaller scale, fewer tourists, secluded beaches and bays—ideal if you want privacy and simplicity.
- Value & easy island-hopping: Potentially lower prices for lodging and food; quick boat-hops to tiny islands like Bequia, Mustique (exclusive), Mustique day trips, and Tobago Cays for snorkeling.
- Laid-back Caribbean culture: Friendly locals, fresh seafood, rum shops, and relaxed island pace.
Risks & downsides
- Hawaii: Longer intercontinental flights for many travelers (time/cost), more tourists at major sights, higher prices overall (especially for luxury resorts and activities).
- St. Vincent: Late September sits in the Atlantic hurricane season (peaks Aug–Oct); increased risk of rainstorms or cancellations. Smaller islands have more limited medical/tourist services and fewer high-end resort options.
Decision factors to weigh
- Travel time & cost: If you’re traveling from North America west coast, Hawaii is shorter and often direct. From Europe, both are long; St. Vincent may be cheaper once there but flights can be indirect.
- Risk tolerance: If you want minimal weather risk, Hawaii is safer in late September than the Eastern Caribbean.
- Desired honeymoon style: Choose Hawaii for dramatic nature, activities, and resorts; choose St. Vincent for seclusion, quieter beaches, and island-hopping authenticity.
- Budget: Compare flight + resort packages. Hawaii tends to cost more for comparable luxury, but deals exist in shoulder season.
Practical tips
- If picking St. Vincent in late September: buy travel insurance with weather/hurricane coverage, confirm flexible booking/cancellation policies, and plan indoor backup activities.
- If picking Hawaii: choose an island that matches your vibe—Maui for romance and beaches, Kauai for lush scenery and hiking, Big Island for volcanoes and unique landscapes, Oahu for nightlife and convenience.
- Book key reservations (accommodations, special dinners, tours) early for both destinations to secure honeymoon extras.
- Consider a split trip: one island in Hawaii or combine St. Vincent with nearby Grenadines islands for variety.
Quick recommendation
- Want “once-in-a-lifetime” dramatic landscapes, dependable service, and lower weather risk: go Hawaii. Prefer intimate, lower-key Caribbean charm and are OK with some hurricane-season uncertainty: choose St. Vincent (with strong travel insurance).
If you tell me your departure city, budget range, and whether you prefer adventure (hiking/volcanoes) or relaxation (secluded beaches), I can recommend a specific island and sample itinerary.