Where Is It Warm in December?

Thailand is in the middle of its best stretch: Bangkok around 88 °F, Phuket 84 °F, with the rain gone and the humidity down. The Caribbean is at the start of its peak season, dry and outside hurricane season. Dubai at around 79 °F is mild rather than hot and is at its most walkable. And the southern hemisphere is in summer, which is why Cape Town and Sydney read as warm in the northern midwinter.

The Indian Ocean has some of the warmest water of the year in December — Bali, Zanzibar and the East African coast are all around 86 °F — which is what makes them a Christmas destination rather than a coincidence.

December's numbers reward reading past the headline. Bali shows an 86 °F sea, among the warmest anywhere, with 466 mm of rain — the wettest figure in the year's data. Turks & Caicos is cooler in the water at 81 °F but takes 44 mm and logs 315 hours of sun.

Zanzibar sits between them at 86 °F air, 86 °F sea and 107 mm. The Canaries are the European floor: Fuerteventura at 66 °F air and a 71 °F sea, dry at 13 mm, mild rather than warm.

December has a cliff edge, and it falls around the 18th. Before it, fares behave like a normal low-season month and the first week is among the cheapest of the winter. After it, they behave like nothing else in the year. If the holidays themselves are fixed, book three to five months ahead — December is the one month where waiting reliably costs money.

Three things move a fare more than the destination does. Book six to eight weeks ahead for short-haul and two to three months for long-haul or peak season — later than that and you are usually paying for someone else's cancellation. Fly midweek: leisure demand clusters on Friday evenings and Sunday returns, and a Tuesday departure is routinely cheaper for the same trip. And shift your dates before you shop for airlines — a day or two either side of a holiday weekend saves more than any loyalty programme. The low fare calendar shows which days are actually cheapest on our busiest routes.

Every temperature on this page is the average daily high for that destination in that month, measured rather than estimated. The sea and rainfall filters come from the same source. Drag either end of the range to change what counts as warm — the list re-sorts instantly, warmest first.

The strongest question Americans ask in December has a domestic answer. Puerto Rico averages 82 °F with the sea at 81 °F and needs no passport, no customs queue and no currency — and it is the cheapest warm destination on this page from most of the country: $146 round trip from New York, $126 from Miami, $147 from Austin, $157 from Tampa, $180 from Minneapolis. The US Virgin Islands are 79 °F with an 81 °F sea. Honolulu is 77 °F and cheapest from the west: $253 from Phoenix, $270 from Dallas and San Diego, $288 from Los Angeles. The Florida Keys sit at the bottom of the range but stay swimmable.

Beyond that the honest answer is that December is expensive, and no amount of searching changes it. Turks & Caicos is $399 from New York, the Cayman Islands $385, Punta Cana $372, Aruba $349 — and Belize is $1,137. These are not badly-timed bookings; they are what the Caribbean costs in the fortnight everyone wants it. The one real outlier is the Yucatán: Cancún and Tulum run $156 from Denver, $170 from Chicago and $171 from Los Angeles, because the route is flown by low-cost carriers at volume from cities the Caribbean is not.

So the choice in December is usually between paying peak for the island you pictured, flying to Mexico instead, or staying inside the US and getting 82 °F for the price of a domestic hop. A page that tells you there are cheap Caribbean flights in late December is telling you something the fares do not support.