Mazatlan in September: Weather, Rain Days, Sea Temperature and Travel Advisory

MAZATLAN · SEPTEMBER · SINALOA, MEXICO

Mazatlan in September is a warm-water month with a rain clause. The sea sits at 89.2°F, afternoons average 91.6°F, and the nights hold at 77.2°F. The clause is 12.4 days of measurable rain and 8.35 inches in all.

The choice that matters is September or October. October cuts the rain to 3.39 inches and keeps the sea at 87.7°F (Open-Meteo marine average). For other months, start with our month-by-month planner.

On this page

• Mazatlan weather in SeptemberHighs of 91.6°F, lows of 77.2°F and 12.4 rain days
• Can you swim in Mazatlan in September?A sea at 89.2°F and what that average measures
• How busy is Mazatlan in September?Sinaloa’s 3% lodging tax, booking terms and the one upgrade worth paying for
• Things to do in Mazatlan in SeptemberEl Faro, the historic center, the Malecon and the islands
• Mazatlan itinerary for SeptemberTwo days built around sunrise and the midday heat
• Mazatlan in September vs August and OctoberRain falls from 8.35 to 3.39 inches next month
• Is September a good time to visit Mazatlan?Who it suits and when to go instead

Settle one thing before flights. The U.S. State Department’s Mexico travel advisory rates Sinaloa, the state where Mazatlan sits, at Level 4, “Do not travel.” We read it on September 29, 2026, and give the rating without its full text. The current wording is on travel.state.gov and can change. Ask your insurer how it treats a Level 4 destination, and book only what you can cancel.

Mazatlan weather in September: average highs, lows and rain days

The air figures in the normals below come from the Servicio Meteorologico Nacional, Mexico’s national weather service, under CONAGUA. They are its 1981-2010 official normals from station 25062, the Mazatlan observatory. September averages a high of 91.6°F and a low of 77.2°F, with 8.35 inches of precipitation. That thermometer stands in the historic center. The Zona Dorada hotel strip and Cerritos beach, a few miles north, are not measured separately, so treat the numbers as the city’s climate and not a reading taken at your pool.

The weather service counts 12.4 days of measurable rain in an average September, a little over two days in five. Its threshold for “measurable” is not published on the station sheet. The data we read does not say at what hour the rain falls, so give every outdoor plan a covered backup. We hold no storm-track data for Mazatlan, so check the forecast in the week before you fly.

The average high and low are 14.4 degrees apart, and a 77.2°F low means the night gives little relief. Pack for heat around the clock: breathable shirts, a hat, sandals and a compact umbrella or light rain shell. A sweater is only for air-conditioned restaurants.

On September 15 daylight runs about 12 hours 19 minutes. The sun rises at 5:51 a.m. and sets at 6:09 p.m. local time (the source gives 12:51 and 01:09 UTC, which we converted to Mazatlan’s clock). Anything that needs light, from the lighthouse viewpoint to a Malecon stroll, has to fit before that sunset.

Can you swim in Mazatlan in September? Sea temperature

The sea off Mazatlan averages 89.2°F in September, according to the Open-Meteo Marine API’s 2015-2024 average. That figure is a mean of daily maxima, a shade warmer than a 24-hour mean. Sea-temperature tables that average over the full day can read lower.

At 89.2°F the water sits only 2.4 degrees under the average afternoon high of 91.6°F. A swim here is a warm soak rather than a cold plunge, and it will not cool you down much on a hot afternoon. Sunscreen and shade matter more than a wetsuit.

Our sources carry nothing on wind, swell or currents for September, so we say nothing about wave height. Ask locally before you swim past the shallows or book a boat, because we have no reading to offer.

How busy is Mazatlan in September? Crowds and prices

We found no occupancy series and no monthly hotel-rate series for Mazatlan, so we crown no month cheap or expensive. The only evidence we hold is the weather. September sits between August’s 8.85 inches of rain and October’s 3.39 inches, with the wettest weather already behind it.

We have no data on how far ahead to book, so we give no number of weeks. Choose rates you can cancel, because the forecast and the Level 4 rating for Sinaloa can both shift before you fly. For general booking habits, our travel basics cover the ground.

Sinaloa’s lodging tax, the Impuesto Sobre Hospedaje, is set at 3% under Article 27 of the state’s Ley de Hacienda. We took the rate from the Gaceta Parlamentaria of February 13, 2024, and El Contribuyente and J.A. del Rio confirm it unchanged for 2026. Whether your hotel folds the tax into its quoted rate or adds it at checkout, we could not verify.

The one place where paying more changes the month is the room’s air conditioning. With an average low of 77.2°F the night does not cool, so a room that holds cold air matters more than a view. We hold no rate data, so we cannot say what that costs.

Things to do in Mazatlan in September

September’s advantage is the water. At 89.2°F, level with August, the sea is the warmest of the three months (October reads 87.7°F in the same Open-Meteo data). Boats and beaches move up the list. The whale-watching trips from the marina follow humpbacks that visit in winter, so they belong to another season.

Start with El Faro, the lighthouse on Cerro del Creston, 157 meters above sea level. Below it, the historic center sits inside a federal Zona de Monumentos Historicos, decreed March 12, 2001, and the Angela Peralta Theater stands within that zone. On the water, Isla de la Piedra lies a few minutes across the harbor entrance by panga from a pier near El Faro. Farther out, Venados, Pajaros and Lobos form a federally protected natural area that only boats reach.

We could not confirm fares or schedules for the pangas, and we have nothing on the island boats, so ask at the pier before you board. In September the air decides the timing more than the water does. The sea holds at 89.2°F while the air runs from a 77.2°F low to a 91.6°F high. Early crossings and shaded streets at midday keep the heat manageable.

Our sources carry no admission fees, so we cannot say what is free by the book. The Malecon is an open-air oceanfront promenade linking the historic center to the Zona Dorada hotel strip. Zona Dorada and Cerritos Beach, further north, are the city’s main hotel-strip beaches.

Mazatlan itinerary for September

Day one. Be at El Faro for sunrise at 5:51 a.m., with the air near the bottom of its 77.2°F to 91.6°F range. Spend the midday high indoors, in air conditioning or the hotel pool. Return to the Malecon late in the afternoon and walk it toward the Zona Dorada until the sun sets at 6:09 p.m.

Day two. Take a panga from the pier near El Faro across to Isla de la Piedra in the morning, then spend the afternoon in the historic center and around the Angela Peralta Theater. If showers arrive (two days in five carry measurable rain), swap the order. Do the historic center first and cross to the beach on the next dry stretch, since the sea stays at 89.2°F either way.

Mazatlan in September vs August and October

Between August and September the air barely moves. Highs go from 92.1°F to 91.6°F and lows from 77.5°F to 77.2°F, while rain eases from 8.85 to 8.35 inches and from 13.1 to 12.4 days. October is where the change lands, with a 90.3°F high, a 74.3°F low, 3.39 inches of rain and 4.2 rain days. The sea holds at 89.2°F in both August and September, then reads 87.7°F in October. The air figures are SMN’s 1981-2010 normals for station 25062.

Sliding to October gives you 4.96 inches less rain and 8.2 fewer rain days. Nights run 2.9 degrees cooler, and you give up 1.5 degrees of sea warmth. Sliding back to August gains nothing, since highs are only 0.5 degrees hotter and the rain is heavier. We hold no rate data, so we cannot say whether either shift saves or costs money.

Is September a good time to visit Mazatlan?

Yes, if you want a 89.2°F sea and can live with 12.4 rain days, heat that stays around 91.6°F, and plans that bend around a shower. No, if you need a dry sky every day or the Level 4 advisory for Sinaloa rules the trip out for you, your employer or your insurer.

If the answer is no on rain, aim for October. It brings 3.39 inches, 4.2 rain days and a sea at 87.7°F. For destinations beyond this city, our destinations index is the place to browse.

September is the last of the three months still holding an 89.2°F sea before October’s 87.7°F and 3.39 inches of rain.

The last word

Sort the advisory and your refund terms first, then let the sea do the rest. You will land at General Rafael Buelna International Airport (MZT), operated by Grupo Aeroportuario Centro Norte (OMA) and southeast of downtown. Give your first clear morning to El Faro for the 5:51 a.m. sunrise, with a hat and water, and keep the afternoon for the pool.

Sources & data for this guide

• Air normals (highs, lows, precipitation, rain days) · Servicio Meteorologico Nacional (CONAGUA), 1981-2010 normals, station 25062 Mazatlan (Obs) · checked Sep 30, 2026
• Sea surface temperature · Open-Meteo Marine API, 2015-2024 mean of daily maxima · checked Sep 30, 2026
• Sunrise, sunset and daylight on Sept 15 · sunrise-sunset.org, converted from UTC to local time · checked Sep 30, 2026
• Lodging tax, 3% · Gaceta Parlamentaria (Camara de Diputados), Feb 13, 2024, citing Article 27 of Sinaloa’s Ley de Hacienda; rate confirmed unchanged for 2026 by El Contribuyente and J.A. del Rio · checked Sep 30, 2026
• Travel advisory, Sinaloa Level 4 · U.S. Department of State · checked Sep 30, 2026
• Historic zone decree of March 12, 2001 and the Angela Peralta Theater · INAH, Catalogo Nacional de Monumentos Historicos Inmuebles; Secretaria de Cultura · checked Sep 30, 2026
• El Faro, 157 meters · Ayuntamiento de Mazatlan municipal tourism portal · checked Sep 30, 2026
• Protected islands (Venados, Pajaros, Lobos) · SEMARNAT · checked Sep 30, 2026 · we did not find the decree date, and a UNESCO year sometimes cited by secondary sources could not be confirmed, so we do not use it
• Airport operator · OMA (oma.aero/mazatlan) · checked Sep 30, 2026
• The Malecon, the beaches, the pangas and the winter whale season are general knowledge. We could not verify panga fares, island-boat schedules, admission fees, hotel rates, occupancy or storm data, so none appear. Hours and conditions change, so check with operators when you book.