Cancun in December: Weather, Sea Temperature and Holiday-Week Crowds

CANCUN · DECEMBER · 21.2° N

December in Cancun runs 78.7°F by day and 73.3°F at night, with 2.10 inches of rain spread across 5.8 days. The sea off the hotel zone averaged 81.5°F. What the month takes back is light: 10 hours 54 minutes on December 15, with the sun gone by about 6:09 p.m., so a day trip that starts at noon finishes in the dark.

November was warmer in both air and water, by 1.5°F and 2.2°F, and wetter by more than a full inch. January cools another degree and puts slightly more rain on the calendar in total. That leaves December at the point where the wet season has drained away but the Caribbean has not yet given up its summer heat, with Christmas and New Year sitting in the second half of the month.

On this page

• Average highs, lows and rain days78.7°F days and 5.8 wet days
• Sea temperature in December81.5°F, and the footnote it needs
• Crowds and the holiday weeksHow busy December gets, and when to book
• Things to do in DecemberBeaches, the lagoon side and the inland ruins
• A two-day plan for a December tripHour by hour, clear day and wet day
• December vs November vs JanuaryHow the three months compare
• Is December a good time to visit?Our verdict, and the month to shift to
• The best month in Cancun overallThe twelve-month view

Where to sleep, how many nights Cancun is worth and which month wins across the year belong to the twelve-month verdict. The month that follows, 1.0°F cooler by day and 0.8°F cooler in the water, has its own page: Cancun in January.

Cancun weather in December: average highs, lows and rain days

Every figure here comes from ECMWF’s ERA5 reanalysis served through Open-Meteo, averaged over 1991-2020 for the model grid cell centered on 21.1743° N, 86.8466° W. That is a modeled cell over Cancun on the Caribbean coast of Quintana Roo, not an airport station reading, and the distinction earns a sentence: a reanalysis interpolates where a thermometer measures. The cell also describes the coast and nothing behind it. The inland Yucatán runs hotter and drier than 78.7°F and 2.10 inches.

Measurable rain lands on 5.8 days out of 31, roughly one day in five, and those 2.10 inches arrive in small helpings: in an average December no single day reaches a full inch. On the ground that reads as a gray half hour rather than a washout, and a 3 p.m. shower costs you the last swim, not the day. One indoor or inland afternoon per week absorbs the whole statistic.

Day and night sit 5.4°F apart, 78.7 down to 73.3. Nothing in that gap calls for a coat. A long-sleeve shirt handles the evening, the ferry deck and the restaurant air conditioning, and the more useful item in the bag is a light rain shell, which beats an umbrella on an open beach. Sunscreen is the one thing December does not excuse you from at this latitude.

Sunrise on December 15 falls around 7:16 a.m. local and sunset around 6:09 p.m., giving 10 hours 54 minutes to work with. Plan the water for the morning half of that. Anything leaving at 4 p.m. finishes in the dark, and the drive back from a ruin or a cenote becomes a night drive if you set off after five. Dinner in Cancun is an after-dark event all month, whatever hour you sit down.

Can you swim in Cancun in December? Sea temperature and what it feels like

The surface off Cancun averages 81.5°F in December, and that number carries a footnote worth reading: it is the mean of daily maxima over 2015-2024 from Open-Meteo’s marine model, so it sits a shade above a true 24-hour average of the same water. Read it as the afternoon surface rather than the dawn surface, and expect other tables to quote you a degree or so lower for exactly that reason.

At 81.5°F you walk in without the gasp. Air averaging 78.7°F means the sea is the warmer of the two for much of the day, so the cold part of a December swim is climbing out, especially into wind or after the sun goes at 6:09 p.m. Children will stay in until they are ordered out. Anyone whose benchmark is an August swim will feel the two degrees the calendar has already taken since November.

Wind and swell are the gap in our December data. The sources behind this month cover air temperature, rainfall, daylight and sea surface temperature, and none of them carries a wind or wave series for this stretch of coast, so we will not tell you how often a norte roughs up the open Caribbean side. Ask the hotel or the boat operator the day before, and keep the sheltered lagoon side of the hotel zone as the fallback.

How busy is Cancun in December? Crowds and how far ahead to book

No monthly hotel rate series for Cancun sits in our sources for this month, so calling December the cheapest or the priciest month of the year would be invention, and it is not going in. The calendar is firmer ground. Christmas falls on the 25th, New Year’s Day on January 1, and school holidays across the United States, Canada and Mexico overlap both, which concentrates demand into the back end of the month.

Those two weeks behave nothing like the first three. Flights and rooms over Christmas week and New Year week compete with every family whose kids are out of school, while early December is an ordinary dry-season stretch with the same 81.5°F water. We hold no occupancy figures to turn that into a number of weeks ahead, so the working rule is plain: lock the holiday-week dates the moment they are firm, and keep the early half of the month as your flexible option.

On the visitor levy: if one applies to your stay in Quintana Roo, we could not verify its current amount or how it is collected from a primary source before publishing, so no figure goes here. The practical move is the same either way. Ask for the all-in nightly total in writing, taxes and any per-night charges included, before a deposit leaves your card.

With 10 hours 54 minutes of daylight, the upgrade that changes this month is location rather than thread count. A room you can walk to the sand from turns the hour after 7:16 a.m. into swimming time. A room that needs a car or a taxi first spends the scarcest part of a December day sitting in traffic on the hotel zone boulevard, and you never get that hour back at the other end.

Things to do in Cancun in December

Two conditions overlap only now. The sea still reads 81.5°F, warmer than January’s 80.7, while rainfall has already fallen to 2.10 inches from November’s 3.18, and measurable rain shows up on 5.8 days instead of 7.4. A full day committed to the water, or to an open archaeological site with no shade, carries better odds in December than in either neighbor at this water temperature.

Name the targets: Playa Delfines on the open Caribbean face of the hotel zone, the flat water of the Nichupté lagoon side when the coast is choppy, Isla Mujeres by passenger ferry, and the inland pair, Chichén Itzá and Tulum, each a full day with a drive at both ends of that 10 hours 54 minutes. Ferry fares, site tickets and opening hours change year to year: confirm them with the operator the week you go.

The month changes the air around those places far more than the places themselves. Stone at Chichén Itzá is the same in June and December; the plaza you cross it on is a 78.7°F afternoon instead of a summer one, and the shadeless hour becomes bearable. Same logic on Isla Mujeres, where the swim is two degrees cooler than in November and the walk between beaches is the part that improves.

Nothing dated and free turns up for Cancun in December in our sources, so no festival is listed here and none is invented. The no-cost hours are the ordinary ones: the public beaches, and a sunrise at 7:16 a.m. late enough that you can be standing on the sand for it without setting an alarm.

Cancun in December: a two-day itinerary

Day one runs against 7:16 a.m. and 6:09 p.m. Swim before 8, when the water reads 81.5°F and the sand is still empty. Breakfast after. Put the boat, the snorkel trip or the Isla Mujeres ferry in the morning half of the day, be back on land by 3, and use the last clear hour on the beach rather than in a taxi. Dinner starts after dark in December no matter how early you sit down.

Day two goes inland: an early start for Chichén Itzá or Tulum, the site walked in 78.7°F air, the drive home finished before the light goes. If the sky turns, the odds are on your side at 5.8 wet days and no day in an average December reaching a full inch, so the shower passes. Move the boat to tomorrow morning, swap the open coast for the lagoon side and give the middle of the day to something with a roof.

Cancun in December vs November and January

Across the three months the average high slides 2.5°F and the sea slides 3.0°F, both gently. Rainfall moves more than temperature. November’s 3.18 inches over 7.4 days drops to 2.10 inches over 5.8 in December, then the total climbs back to 2.41 in January while the count of wet days falls again to 5.5. Of the three, December holds the lowest rainfall total, and January the fewest days on which any of it falls.

Shift four weeks earlier and you gain 1.5°F of air and 2.2°F of water, and you take on 1.6 extra wet days and an additional inch of rain. Shift four weeks later and you give up 0.8°F of sea and 1.0°F of daytime air, keep the low day count, and step clear of the holiday weeks altogether. That trade is laid out in full on Cancun in January.

Is December a good time to visit Cancun?

For a warm-water vacation with low rain risk, yes, and the numbers back it: 81.5°F water, 78.7°F days, rain on fewer than one day in five. The month works against you on two fronts. Daylight is short at 10 hours 54 minutes, which squeezes any itinerary built on long drives, and the final two weeks are the most contested dates of the Cancun year for flights and rooms.

If those two weeks are your only window and the budget is tight, take January instead: 5.5 wet days, water still at 80.7°F, and a calendar with nothing in it after New Year. Want the warmest possible sea and can live with the rain? November’s 83.7°F is the trade, paid for with 7.4 wet days and 3.18 inches. The full ranking sits in the twelve-month verdict.

What no other month in this trio offers is the pairing itself: 81.5°F water and only 2.10 inches of rain in the same four weeks.

The last word

Book the first three weeks if your dates move at all: the water reads 81.5°F on December 3 exactly as it does on December 28, and only one of those dates makes you fight for a flight. One caveat on the arithmetic above, since it is easy to miss. The sea figure rests on ten years of marine model output, 2015-2024, while the air normals rest on thirty, 1991-2020. They are not the same kind of average, and neither one is a forecast, so check the five-day before you decide whether the rain shell goes in the bag.

Sources & data for this guide

• December air normals (78.7°F high, 73.3°F low, 2.10 in, 5.8 days at 0.10 in, 0.0 days at 1 in) · Open-Meteo / ECMWF ERA5, 1991-2020, model grid cell 21.1743° N, 86.8466° W · a model reanalysis, not an airport station reading · checked Sep 15, 2026
• November and January normals used in the comparison table · same ERA5 series and same 1991-2020 period · checked Sep 15, 2026
• Sea surface 81.5°F in December (83.7°F November, 80.7°F January) · Open-Meteo Marine API, mean of daily maxima 2015-2024 · a shorter and different baseline from the air normals · checked Sep 15, 2026
• Daylight of 10 h 54 min on December 15, sunrise 12:16 UTC and sunset 23:09 UTC, converted to local time · sunrise-sunset.org · checked Sep 15, 2026
• No monthly hotel rate series, no occupancy series and no current visitor-levy amount could be verified for Cancun before publishing, so none is quoted · ferry fares, site tickets and opening hours change · confirm with operators when you book.