Seaweed on your beach? A private catamaran to Isla Mujeres from $900.
See the catamaranShort answer: sargassum season in Cancún and Tulum usually peaks between May and August and eases through the fall. The box below is updated every day with the latest state beach map, beach by beach.
Cancún weather is warm every month of the year, so the useful question is not whether it will be hot but which kind of trip each month suits. The answer depends on three things: how much rain falls, where you sit in hurricane season, and how much sargassum reaches the beach you chose.
This guide uses long-term climate averages for Cancún and the sargassum reports published through September 2026. Tulum sits about 130 km south of Cancún and shares the same general pattern, though its beaches tend to catch more seaweed. Sargassum changes from one year to the next, so treat everything here as a pattern, not a promise.
The climate in numbers
Climate normals for 1991–2020 put Cancún's average daily highs between 29°C (84°F) in January and 35°C (95°F) in July and August. Overnight lows run from about 20°C (68°F) in January to 25°C (77°F) in the summer. Relative humidity stays between roughly 72% and 83% all year, which is why the same temperature feels milder in February than in August.
Rain is the clearer seasonal signal. Annual precipitation is about 54 inches (roughly 1,370 mm), and it is concentrated late in the year. October is the wettest month at 10.9 inches (277 mm), with June and September also heavy at about 7 inches (180 to 185 mm). March is the driest at 1.5 inches (39 mm), followed by April at 1.7 inches (43 mm) and February at 2.3 inches (58 mm). Most rain arrives as short heavy downpours, not all-day grey.
Hurricane season, plainly
The Atlantic hurricane season runs from June 1 to November 30. According to NOAA's National Hurricane Center, the statistical peak is around September 10, and most activity falls between mid-August and mid-October. An average season brings 14 named storms and 7 hurricanes, and only a fraction of those come near the Yucatán Peninsula.
For a stay in the peak weeks, the practical advice is simple. Choose flexible bookings, keep travel insurance that covers named storms, and let your concierge watch the forecast. Villas built with hurricane shutters and backup power make a real difference. Plenty of September and October days are perfectly good, and rates are lower, but the risk of a disrupted itinerary is higher than in winter.
Sargassum: what the pattern looks like
Sargassum is a floating brown seaweed that drifts across the Atlantic and lands on Caribbean coasts. It tends to arrive in the warmer half of the year, with the heaviest weeks usually between about May and August. In 2025 the Mexican Caribbean collected roughly 93,000 to 96,000 tonnes depending on the report, and 2026 passed 123,400 tonnes by early September.
The University of South Florida's Optical Oceanography Lab, which tracks the seaweed by satellite, said in its July 31 outlook that 2026 is on course to be the second-largest sargassum year on record, behind 2025. It also expects amounts to keep decreasing in most regions until possibly November. Reports from Quintana Roo in September said that decline had started in mid-August, with about 75% of northern beaches showing low presence and minimal sargassum expected in November and December.
The pattern is not uniform. In April 2026 the state monitoring network counted 17 of 100 northern beaches at red alert, while in July the worst-affected list included Tulum, Akumal, Puerto Aventuras and Playa del Carmen. Cancún and Isla Mujeres tend to recover faster, and the exact weeks vary with wind and current.
Which beaches are usually less affected
No beach is guaranteed clear, but a few are consistently better. Playa Norte on Isla Mujeres recovered its Blue Flag status in 2026 after the municipality collected about 1,500 tonnes of sargassum from January to April, and Costa Mujeres moved from an orange to a green flag in the same report. Local coverage has also named Cancún's Gaviota Azul, Chac Mool and Delfines beaches among the least affected when conditions eased, along with Cozumel's western side.
Holbox Ferry, Isla Contoy and Isla de la Pasión were listed as sargassum-free on the state's June 29 traffic-light report, even in the middle of a heavy year. The Caribbean-facing beaches south of Playa del Carmen, including Tulum, take the most hits because they face the incoming current head on.
Cancún weather month by month
Temperatures are average highs and lows from 1991–2020 normals. Sargassum notes describe the usual pattern and not a forecast.
January
Cool evenings, mostly dry, high season. Sargassum is typically light.
February
Dry and clear, one of the best months for yachts and long beach days.
March
Driest month. Spring break is now much smaller than it was; Cancún projected about 27,000 spring-break visitors in 2026 against a peak of 520,000. Sargassum starts to build.
April
Hot, dry and bright. Seaweed was already heavy in the north in 2026, so check conditions.
May
Heat and humidity rise, first rains. Sargassum often begins its heavier run.
June
Hurricane season opens on June 1. Whale sharks begin around Isla Mujeres and Holbox.
Hurricane seasonJuly
Hottest month, with whale sharks at their peak. Sargassum usually near its worst.
Hurricane seasonAugust
Still hot and humid. Sargassum eased from mid-August in 2026.
Hurricane seasonSeptember
Hurricane peak is around September 10. Whale shark season ends this month. Lowest prices.
Hurricane seasonOctober
The wettest month. Storm risk remains until the season closes.
Hurricane seasonNovember
Rain and humidity drop, hurricane season ends on the 30th, and Day of the Dead is observed on November 1 and 2. Sargassum is usually minimal.
Hurricane seasonDecember
Pleasant and dry, and the holiday weeks are the busiest and most expensive of the year.
Best months by plan
For yacht days, February through April gives the driest weather, calm mornings and the most predictable sea. November and December are a close second, with lower humidity and usually little seaweed. Summer yachting still works, but expect heat and the odd afternoon squall.
Whale sharks are a summer experience. Sources agree the season around Isla Mujeres and Holbox runs from about June to September, with July and August as the peak, so book early for those weeks. For villa stays, December to April is the comfortable core, while May to August suits guests who prefer a pool villa, an air-conditioned base and boat days, and September to October suits flexible travelers who want value.
Best months for a boat day: private catamaran to Isla Mujeres from $900 →
Bachelorette in Tulum: boat party from $1,000 →
How to check sargassum before you go, and what to do if it shows up
Start with the Red de Monitoreo del Sargazo in Quintana Roo, which publishes a daily traffic-light report by beach, and the USF Optical Oceanography Lab's monthly outlook. Mexican Navy (SEMAR) updates and local news give a day-by-day view. Look at your specific beach, not the whole coast, since conditions can differ between neighboring beaches. Ask your concierge for a check on the morning of arrival.
If your beach has seaweed, you have good options. A yacht or catamaran to Isla Mujeres puts you on Playa Norte or in clear water off the reef within a short crossing. Cenotes inland are unaffected, and Holbox and Isla Contoy were among the cleanest places on this year's reports. A pool villa also keeps the day intact whatever the sea does.
- Check the traffic-light report 3 to 5 days out, then again the morning of your beach day.
- Plan a flexible day for a boat trip to Isla Mujeres, and book it once conditions are clear.
- Schedule cenote visits as your backup activity, ideally on mornings you would otherwise spend on the beach.
If your beach has seaweed, go out by boat: Playa Norte on Isla Mujeres is usually less affected →
