Dec 28-30
Hello, We are going to Miami for family wedding at the end of December. We are thinking we should go for couple of days to Key West. Just wondering the weather last two in December. Is it really cold there? We are from Boston but it doesn’t mean we can put up temp around 50 degree or so. Is the water cold for swim or any activity?
Me and husband don’t swim but kids do. Is it good weather for take boat ride? Please advise.
If not Key West then what other option I have? Thank you!
Great question. Visiting Key West from December 28–30 is generally a really nice idea — the weather is quite mild, not cold by Florida standards, and water activities are still very possible. That said, there are some nuances, especially when coming from a place like Boston where “50 °F” might feel pretty normal — but in Key West, that kind of cold is very unlikely in late December.
Here’s a detailed breakdown of what you can expect for weather, water, and activities — plus a few alternative ideas if Key West doesn’t feel quite right for those dates.
What the Weather Is Like in Key West at That Time
- The air temperature in Key West around late December typically averages in the mid-70s °F during the day. Nighttime lows are often in the upper 60s.
- It’s not very rainy — December is relatively dry, with only a few light showers on average. Humidity is moderate; not stifling, but enough to feel “tropical” rather than crisp.
- Because the sky tends to be fairly clear and there is decent sunshine, late December days are often pleasant and “beach-friendly” for those used to colder climates.
Water Temperature & Swimming
- The sea water temperature in Key West during late December averages around 74–77°F (23.6–24.5 °C) depending on the source. Other data show similar ranges: average ~75 °F, with minima around 73 °F and maxima nearer 77 °F.
- That water temperature is quite comfortable for swimming, especially for people who come from colder climates — many visitors swim without wetsuits. Some locals note that a *thin wetsuit* might feel more comfortable for longer stays in the water, but it's not always necessary.
- According to people who have visited in December, swimming is still quite common: > “You can absolutely swim … The water is usually around 74-78 … If it's too cold … see about a thin wetsuit.”
Boat Rides & Other Activities
- Late December is generally good for boat rides, as long as the weather is calm. The daytime air temperatures and sea conditions are usually very favorable for excursions. Locals mention that calm water days are common, though winter (including December) can bring some wind or “northerly” fronts that occasionally make boating a little bumpier.
- Because you and your husband don’t swim, boat tours (sightseeing, sunset cruises, snorkeling trips with short stops) can be a great way for the kids to enjoy the water while you relax on deck.
- If you go out on a boat, especially for longer rides, it’s wise to bring a light jacket or sweatshirt — evenings or breezy moments can feel cooler. Local advice often recommends this.
Risks / Things to Watch For
- There *is* a small chance of a cold front: on some years, December sees a brief dip in temperature, which could bring somewhat windier conditions or slightly cooler air/water.
- Because the water is not as warm as in peak summer, visibility or comfort for snorkeling or diving may vary; if you do want to do more serious water activities, check with local tour operators for recent conditions.
- Shorter daylight: December days are a bit shorter, so plan any afternoon boat rides or water activities accordingly.
So — Is Key West a Good Option for You for December 28–30?
Yes, I think Key West is quite a good option. The weather is mild, not cold like a New England winter, and many visitors (including families) find it comfortable for both relaxing and doing water-based activities. The sea is warm enough for your kids to swim, and boat rides are very feasible. While you can’t guarantee perfectly calm water every single day, the odds lean in your favor for a lovely mini getaway from the wedding.
Alternative Destinations to Consider
If for any reason Key West doesn’t feel like the right fit for your trip (or if weather forecasts closer to your trip suggest rougher or windier conditions), here are a few other options in Florida to think about:
- Miami / South Beach: Since you’re already going to Miami, you could extend your stay there. December weather is very comfortable, and there are lots of beaches, boat tours, and water-friendly activities (plus great family-friendly dining).
- The Florida Keys but slightly north of Key West: Consider Islamorada or Marathon — they are more spread out, maybe a little less “party island” than Key West, but still very scenic and water-activity friendly. Boat rides, snorkeling, and calm keys feel very relaxing.
- The Gulf Coast of Florida: Places like Naples or Marco Island offer calmer seas, beautiful sunsets, and often less wind than the Atlantic side. December is lovely in that region, and it's a good pick if you want a more low-key coastal escape.
Bottom Line: For December 28–30, Key West is very unlikely to feel “cold” to someone used to Boston winters. The water is warm enough for swimming, especially for the kids, and boat rides are a strong bet. Bring a few layers for evenings or breezy moments, but overall, you should have a really pleasant, tropical-feeling break.
