Isla Mujeres in August: Weather, Sea Temperature, Rain and Hurricane Season

ISLA MUJERES · AUGUST · MEXICO

Isla Mujeres in August comes with water at 87.0°F, afternoons at 95.2°F and measurable rain on 11.6 days, all inside the Atlantic hurricane season. The island is a short ferry ride off Cancun and Puerto Juarez, small enough that most visitors get around by golf cart, scooter or bicycle, and the sea is warm enough to make the heat easy to forgive.

Four weeks either way changes the rain more than the heat. July brings 2.64 inches to August’s 4.02, September brings 7.15 inches over 15.1 rain days, and September 10 is the peak of hurricane season. If Isla Mujeres is still one contender among several, our destinations index is the place to compare.

On this page

• Isla Mujeres weather in August95.2°F highs, 77.0°F lows, 4.02 inches of rain
• Can you swim in Isla Mujeres in August?Sea at 87.0°F and what the number means
• How busy and how expensive is August?Lodging tax at 5% or 6%, Visitax at about 293 pesos, ferry rules
• Things to do in Isla Mujeres in AugustPlaya Norte, Punta Sur, Garrafón and Isla Contoy
• A two-day Isla Mujeres itinerary for AugustBeach and town first, the south end second
• August vs July and SeptemberRain at 2.64, 4.02 and 7.15 inches
• Is August a good time to visit?Yes for warm water, no for dry days

August falls inside the Atlantic hurricane season, which NOAA’s National Hurricane Center dates from June 1 to November 30. The season peaks on September 10, with most activity between mid-August and mid-October, so the second half of this month already sits in the busy stretch. Check the National Hurricane Center’s outlook the week you fly.

Isla Mujeres weather in August

Every figure here comes from Mexico’s national weather service (Servicio Meteorologico Nacional, part of CONAGUA): 1991-2020 normals from station 23155 in Cancun. That station sits on the mainland about 8 miles across the channel, and no station on the island has published normals, so read them as the nearest official numbers for Isla Mujeres. An average August reaches a high of 95.2°F and a low of 77.0°F, with 4.02 inches of precipitation.

SMN counts 11.6 days of measurable rain in an average August, closer to three days in eight than to one in ten, and its fiche does not publish the threshold for a rain day. The normals also give counts and totals only, so we cannot say whether the rain arrives as a short burst or a long soak. Pencil in a wet-weather option for any two-day stretch.

Lows of 77.0°F leave only 18.2 degrees between an average night and an average afternoon, so the night brings almost no relief. Pack for heat at both ends of the day: light fabrics, a hat, reef-safe sunscreen, and a dry bag for phone and ID on ferry and boat days. A jacket stays home.

On August 15 daylight lasts about 12 hours 53 minutes, from a 6:24 a.m. sunrise to a 7:17 p.m. sunset (converted from 11:24 UTC and 00:17 UTC to America/Cancun time). Sunset is the cue to swap the water for dinner, and the walk back through town happens after dark.

Can you swim in Isla Mujeres in August? Sea temperature

Open-Meteo’s marine data puts the sea surface off Isla Mujeres at 87.0°F in August, averaged over 2015-2024. That figure is the mean of daily maxima, the warmest reading of each day, so a 24-hour mean would come in a little lower. Other sea-temperature tables may quote different numbers for the same water.

At 87.0°F the water sits 10.0 degrees above the average August night (77.0°F), so there is no cold gasp on entry and most people will skip the wetsuit. It runs warmer than July’s 86.1°F and level with September’s 87.1°F.

We have no August wind or swell reading, so we cannot say how choppy the water runs. Geography gives one lead: Playa Norte faces the island’s north tip, where the current running along the east side breaks, and it is the calmest beach on the island. Punta Sur, at the southern tip, looks out over open water, so ask your boat operator about conditions that morning.

How busy is Isla Mujeres in August? Crowds and prices

We found no occupancy series and no month-by-month hotel rates for Isla Mujeres, so we crown no month expensive and none cheap. Rate cards and availability for your own dates are the only reliable price signal, and with the September 10 hurricane peak just ahead, check both before shifting a trip into early September.

We could not verify how many weeks ahead lodging fills in August, so we give no lead time. The one booking rule we did read is the ferry’s: Ultramar tickets to Isla Mujeres are valid for six months from purchase, are non-refundable, and passengers are asked to arrive 30 minutes before departure. Children under 1.20 meters ride at a reduced fare, and infants under 12 months travel free with a boarding pass.

Quintana Roo’s lodging tax, the Impuesto Sobre Hospedaje, is set at 5% of the billed accommodation value, or 6% when a host or booking platform collects payment for a short-term rental. Every foreign visitor entering the state also owes the Visitax fee: 2.50 UMA, about 293 pesos at the UMA’s 2026 daily value. We did not verify an exchange rate, so we give no dollar figure.

Cancellation terms are the one place where paying more changes an August trip. A flexible rate costs extra (we have no verified premium), and it turns a storm-week forecast into a rebooking instead of a loss, since Ultramar tickets are non-refundable.

Things to do in Isla Mujeres in August

August offers a sea at 87.0°F and nearly 13 hours of daylight on the 15th, enough to fit a boat trip, a beach hour and a cliff walk into one day. None of it is exclusive to the month: July’s sea is 86.1°F and September’s 87.1°F. On rain, August sits between them at 4.02 inches.

Playa Norte faces the north tip of the island and is the calmest beach. Punta Sur, at the southern tip, is a clifftop park with a sculpture garden and a lighthouse over open water. Garrafón, a private reef park on the south end, is commonly sold as a snorkeling and activities day pass, but its site did not load when we checked, so we state no admission price. Isla Contoy, a national park and bird sanctuary north of the island, is reached on boat trips commonly sold from Isla Mujeres. CONANP’s page for the park did not load either, so we give no visitor limits or fees.

Between July and September the sea barely moves (86.1°F, 87.0°F, 87.1°F) while rain runs 2.64, 4.02 and 7.15 inches, so the month changes the sky far more than the water. At Punta Sur, an open clifftop in 95.2°F air, that means going early or late. At Garrafón or on a Contoy boat, the water is the same 87.0°F whatever the clouds do.

We could not verify entry fees or hours for any of these sites, so we name no free list. Walking the main town costs nothing. Golf carts, scooters and bicycles, the usual ways around the island, are priced by the rental shop, so ask before you hire.

Isla Mujeres itinerary for August

Take a morning ferry from Cancun, rent a golf cart or a bicycle, and go straight to Playa Norte while the air is still short of its 95.2°F afternoon high. Spend midday indoors over a long lunch in town, then return to the sand or the water for the last hours of light, with sunset near 7:17 p.m.

Give day two to the south end: Punta Sur’s clifftop and lighthouse early, before the heat builds, then a reef afternoon at Garrafón, or trade the whole day for a Contoy boat trip booked from the island. If rain sets in, water at 87.0°F keeps snorkeling comfortable, so move the reef time forward and leave the clifftop for a clearer hour. Confirm boat departures with the operator the evening before, since we could not read any operator’s terms.

Isla Mujeres in August vs July and September

Highs run 94.6°F in July, 95.2°F in August and 93.6°F in September, and lows hold at 77.0°F, 77.0°F and 76.3°F. Rain moves much more: 2.64, 4.02 and 7.15 inches, on 9.2, 11.6 and 15.1 days. The sea stays between 86.1°F and 87.1°F. The air figures are SMN’s Cancun station, and the sea figures come from the Open-Meteo Marine API.

Moving four weeks earlier trades 95.2°F highs for 94.6°F and cuts the rain to 2.64 inches over 9.2 days, at the price of a sea at 86.1°F instead of 87.0°F. Moving four weeks later takes 1.6 degrees off the afternoon highs, then costs 7.15 inches of rain on 15.1 days and lands you at the September 10 hurricane peak.

Is August a good time to visit Isla Mujeres?

Yes, if warm water matters more than dry days: an 87.0°F sea, rain on 11.6 days, highs of 95.2°F. No, if you cannot plan around a storm forecast or dislike heat that leaves the nights at 77.0°F. The U.S. State Department also rates Quintana Roo Level 2, “Exercise increased caution,” in its Mexico Travel Advisory reissued May 29, 2026, so read the current text before you book.

July is the month to prefer if the answer is no: 2.64 inches of rain on 9.2 days, and a sea still at 86.1°F. It sits inside the same hurricane window, so it is a drier bet and no escape from the storm season. Travelers who want none of that risk can look at months outside June 1 to November 30 in our month-by-month guide.

August pairs an 87.0°F sea with 4.02 inches of rain, a total that sits between July’s 2.64 and September’s 7.15, in 12 hours 53 minutes of daylight on the 15th.

The last word

Book the flexible rate, pack for a 77.0°F night, then choose your dock: Puerto Juarez, Playa Tortugas at kilometer 6.5 of Boulevard Kukulcan, or Playa Caracol at kilometer 9.5. Ultramar sails from all three to the Terminal Maritima APIQROO on the island.

Sources & data

• Air temperature, precipitation, rain days · Servicio Meteorologico Nacional (CONAGUA), climate normals 1991-2020, station 23155 (Cancun, Benito Juárez) · checked Sep 30, 2026
• Sea surface temperature (mean of daily maxima, 2015-2024) · Open-Meteo Marine API · checked Sep 30, 2026
• Sunrise, sunset and daylight on August 15 · sunrise-sunset.org · checked Sep 30, 2026
• Hurricane season dates and September 10 peak · NOAA National Hurricane Center · checked Sep 30, 2026
• Ferry terminals, ticket validity, refund and boarding rules · Ultramar, “Ferry Isla Mujeres” page · checked Sep 30, 2026
• Lodging tax (art. 8) and Visitax (art. 51-Octies) · Congreso del Estado de Quintana Roo · checked Sep 30, 2026
• Travel advisory level · U.S. Department of State · checked Sep 30, 2026
• The island’s beaches, Punta Sur, Garrafón and Isla Contoy are described from general knowledge. CONANP’s page for Isla Contoy and Garrafón’s own site did not load when we checked, so we give no fees, limits or hours for them. The Cancun station is the nearest official climate normal we found, not a reading taken on the island.