Cancun in January: Weather, Sea Temperature and the Holiday Weeks

CANCUN · JANUARY · 21.17° N

Cancun in January runs to an average high of 77.7°F and an average low of 72.0°F. Both are the mildest of the winter stretch here: December afternoons reach 78.7°F, February afternoons 79.0°F, and January nights sit 1.3°F under December’s. Nobody books a flight south for 1.3°F. What that degree does is make the middle of the day workable for a walk on open stone or a long stretch on the sand, and it leaves the water warmer than the air above it.

The rest of the month’s case is light and calendar. January 15 gives about 11 hours and 1 minute of daylight, sunrise near 7:25 a.m. and sunset at 6:27 p.m. local, so an evening on the beach finishes before dinner instead of replacing it. The first days of the month belong to the New Year holiday, which makes booking the opening week a different exercise from booking the closing one. Every figure here comes from a model reanalysis rather than an airport thermometer, and the difference between those two is measurable.

On this page

• Cancun weather in January77.7°F days, 72.0°F nights, 5.5 rain days
• Sea temperature for swimming80.7°F, read as a daily-maximum mean
• How busy the month gets, and what it costsThe New Year week, booking, and what we cannot price
• Things to do in Cancun in JanuaryPlaya Delfines, El Rey, Isla Mujeres, Chichén Itzá
• A two-day plan around 11 hours of daylightDay one on the coast, day two on the water
• January, December or FebruaryHow the three months compare, figure by figure
• Is January a good time to visit Cancun?Yes, with two exceptions

The neighbors carry their own normals: 81.5°F water in December, 1.43 inches of rain across February. If your dates are still movable, read January against both before you buy the flights.

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

The normals here come from Open-Meteo’s ERA5 series, the ECMWF reanalysis rebuilt over 1991-2020 and read for the grid cell at 21.1743° N, 86.8466° W. That cell sits over Cancun itself, on the Caribbean coast of Quintana Roo. It is not an airport station reading, and it is not the interior either: the inland Yucatán behind the coast runs hotter and drier than these figures. On that cell, January averages 77.7°F by day and 72.0°F at night.

Measurable rain, meaning 0.10 inch or more in the day, lands on 5.5 days in an average January, roughly one day in six, and the month totals 2.41 inches. In practice that is a sky that closes over part of an afternoon and opens again. It also means the excursion you most want belongs early in the trip, where there is room to move it, rather than on your last full day.

The gap between the average day and the average night is 5.7°F, small enough that packing is a question of wind and water, not warmth. One long-sleeve layer covers a boat ride out and the restaurants that run their air conditioning hard, a light rain shell covers the one-day-in-six, and nothing in these normals asks for a coat.

On January 15 the sun clears the horizon at 7:25 a.m. and sets at 6:27 p.m. local time, about 11 hours and 1 minute between them, converted from 12:25 and 23:27 UTC. Quintana Roo holds UTC-5 all year, so there is no clock change to plan around mid-trip. A 6 a.m. pickup for an inland day leaves in full darkness, and anything you wanted to photograph on the sand has to happen before 6:30.

Can you swim in Cancun in January? Sea temperature off the coast

The sea surface off Cancun averages 80.7°F in January, from the Open-Meteo Marine API over 2015 to 2024. Read what that number is: a mean of daily maxima, the warmest reading of each day, so it sits a shade above what a 24-hour average would give. Tables that average the full day will print something lower for the same month and the same water, and neither figure is wrong.

Set against an average afternoon air temperature of 77.7°F, the water is about 3°F warmer than the air over it. Entering is a non-event: no gasp, no ten-minute negotiation at the edge. The cold part of a January swim is the exit, when a breeze crosses wet skin at four in the afternoon. Carry the towel.

We could not read a wind or swell series for Cancun in January in our data, so no characterization of the month’s chop appears here, and none has been invented. What the same dataset does say is that rain measures on 5.5 days. Ferry and catamaran operators make their own call on the morning: check the operator’s notice the night before a crossing rather than treating a reservation as a guarantee.

How busy is Cancun in January? Holiday weeks, booking and lodging charges

January opens on the New Year holiday, and that is the one crowd fact with a date attached. Beyond it, our data carries climate, not commerce: no occupancy series, no monthly room rates, no airfare curve for Cancun. So the phrase “cheapest week of the year” does not appear here, because nothing available supports the ranking. What holds is that the first days of January are holiday days in Mexico, the United States and Canada at once.

Treat the month as two bookings. The opening ten nights behave like holiday nights anywhere: fixed dates, little flexibility, booked as far out as your plans allow, with refundable rates taken when the premium is small. The back half of the month is an ordinary booking exercise. That split is a rule of thumb from our desk: no lead-time data for Cancun sits in these sources, and no number of weeks is printed as though it did.

On lodging tax, our sources carry no rate for Quintana Roo, so no figure appears. That is an absence in our data, not a statement that nothing is charged. Ask the property for the all-in nightly total, including any state lodging charge and any resort fee, in writing, before a deposit leaves your card.

The one place where paying more genuinely changes a January trip is the walk between your room and the water. With daylight closing at 6:27 p.m., a hotel that puts the sand five minutes away gives back the hour a shuttle would take out of the short end of the afternoon. A bigger room, in a month whose average high is 77.7°F, buys space you will not be sitting in.

Things to do in Cancun in January: Playa Delfines, El Rey and Isla Mujeres

January’s daytime average of 77.7°F is the mildest of the three winter months by a full degree, and that is the month’s practical gift: an inland archaeological day or a long walk on open stone is easier in January air than in February’s 79.0°F. The water has barely moved, 80.7°F against December’s 81.5°F, so nothing on the swimming side is traded away for it.

Named targets, in rising order of effort: Playa Delfines at the far end of the hotel zone for an open stretch of sand, El Rey and the Museo Maya de Cancún for an hour or two out of the sun, the Puerto Juárez ferry across to Isla Mujeres, and a full inland day to Chichén Itzá. Admission prices, opening hours and ferry timetables are not in our data, and they are not guessed at: take each from the operator’s own page the week you book.

What January changes at those places is the air, not the water. The Caribbean moves 1.3°F across the three winter months, from 81.5°F in December to 80.2°F in February, a slide no swimmer detects. The air over the ruins shifts in the same small range. The real constraint is the 11-hour day: an inland trip and a beach afternoon do not both fit comfortably into one January date.

Nothing in this month’s data flags a free-admission date in January for any Cancun museum, so none is listed here: the museums publish their own calendars. What the month hands over at no charge is light, about 11 hours and 1 minute of it on the 15th, with the sun down at 6:27 p.m., which puts the best hour on the sand somewhere between 5 and 6 p.m.

Cancun in January: a two-day itinerary

Day one stays on the coast. Out around 8 a.m., half an hour after the 7:25 sunrise, with the air still near its overnight 72.0°F: this is the walking hour. Beach from 9 to noon while the water reads 80.7°F. Lunch, then a museum hour through the warmest part of the afternoon. Back on the sand by 4. The sun is gone at 6:27, so dinner begins in the dark whether you planned it that way or not.

Day two goes across the water or inland: the Puerto Juárez ferry to Isla Mujeres, or the long drive to Chichén Itzá leaving before first light. If the date turns out to be one of the 5.5 wet ones, swap the order and keep the plan: El Rey and the Museo Maya in the morning, a look at the sky at 2 p.m., the crossing held for the following day. The operator decides on the morning, so the call is theirs.

Cancun in January vs December and February

Across the three, January sits coolest at both ends: 77.7°F by day against December’s 78.7 and February’s 79.0, and 72.0°F at night against 73.3 and 72.9. The separation is in the rain. February takes 1.43 inches over 3.4 wet days, January 2.41 inches over 5.5, which is two extra days with measurable rain in a 31-day month. The sea drops 0.8°F from December into January and 0.5°F more into February, a slide nobody standing in it registers.

Push the trip four weeks forward and you buy February‘s drier column and give up 0.5°F of water and a degree of night coolness. Pull it four weeks back into December and you get the warmest water of the three at 81.5°F, along with the Christmas and New Year weeks and 5.8 wet days, marginally more than January’s 5.5. Air normals for both months come from the same ERA5 series and period as January’s.

Is January a good time to visit Cancun?

For most travelers, yes. A 77.7°F afternoon, an 80.7°F sea and 11 hours of daylight are the reasons people book Cancun in winter, and the month delivers them on the figures. Two groups do less well: anyone whose vacation collapses if two afternoons go wet, and anyone locked to the holiday week who wants a quiet beach at the same time.

If that is you, February is the shift to make: 1.43 inches over 3.4 wet days against January’s 2.41 over 5.5, for a sea that gives back 0.5°F and daytime air that gains 1.3°F. December runs the other direction, warmest water of the three at 81.5°F, though its second half carries the same holiday pressure January’s first half does.

One line for the month: of these three, January is the only one that pairs the mildest daytime air, 77.7°F, with water still above 80°F.

The last word

The January decision is which half of the month you stand in, and it gets made at the booking stage. Keep the rain in proportion while you make it: the ERA5 cell over Cancun records a full inch of rain on 0.3 days in an average January, roughly one January in three, and most vacations here land outside it. Book the room close to the sand, put the inland day early in the trip where it can move, and take the ferry timetable from the operator rather than from a booking site.

Sources & data for this guide

• January air normals (77.7°F high, 72.0°F low, 2.41 in), 1991-2020 · Open-Meteo / ECMWF ERA5, grid cell 21.1743° N, 86.8466° W · model reanalysis, not an airport station reading · checked Sep 15, 2026
• Rain-day counts (5.5 days at 0.10 in or more, 0.3 day at 1 in or more) · same ERA5 series and period · checked Sep 15, 2026
• Sea surface 80.7°F, mean of daily maxima 2015-2024 · Open-Meteo Marine API · checked Sep 15, 2026
• Daylight, sunrise and sunset for January 15 (12:25 and 23:27 UTC, converted to local UTC-5) · sunrise-sunset.org · checked Sep 15, 2026
• December and February air normals · same ERA5 series and period as January; their sea figures come from the Marine API, 2015-2024 · checked Sep 15, 2026
• No occupancy series, no monthly hotel rates, no lodging tax rate, no site admission prices and no wind or swell series for Cancun appear in the data behind this guide · none has been estimated · check operators and properties when you book.