SeasonMapIsla Mujeres weather in September
Mexico
September in Isla Mujeres: sweltering, soaked, with clean air — fine if you can take 23 rainy days.
#11 of 12 months in Isla Mujeres · #748 of 1383 destinations to visit in September · comfort 78/100 (tier B)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Isla Mujeres in September
Other months in Isla Mujeres
Isla Mujeres's forum calls March the best time of year weather-wise — sunny and hot with pleasant nights, though rainfall stays low rather than absent. Regulars flag March as typically the windiest month locally, and note a passing cold front can still knock a few degrees off the temperature, so a light wrap for the evening is worth having.
Add your own note from Isla Mujeres's card on the map.
Isla Mujeres climate normals — September
| Daytime high | 32°C / 89°F | 🔥 sweltering |
|---|---|---|
| Nighttime low | 25°C / 76°F | |
| Feels like (high) | 38°C / 100°F | |
| Sea temperature | 30°C / 86°F | ♨️ bath-warm |
| Rainfall | 175 mm / 6.9 in | ⛈ soaked |
| Rainy days | 23 days | |
| Humidity | 84% | 💦 very humid |
| Dew point | 25°C / 77°F | |
| Sunshine | 10.5 h/day | |
| Daylight | 12.3 h | |
| Wind | 14 km/h / 9 mph | |
| Air quality (US AQI) | 35 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Isla Mujeres in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Quietschool holidays in 2 of the markets that fill it, one of its worst months for weather(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Isla Mujeres's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherIsla Mujeres's weather doesn't swing hard through the year — comfort stays fairly steady in every month.
What's on in Isla Mujeres in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Hazard
Sargassum season
1 Apr – 30 Sep · usuallyThe east-facing side takes the seaweed and the smell that comes with it once it rots. Playa Norte, tucked behind the north tip, usually stays clear, which is why the island holds up better than the mainland coast. Source ↗
- Nature
Whale shark season
15 May – 17 SepDive seasonBook earlyPermits run mid-May to mid-September for the aggregation twenty-odd miles north of the island. Peak is July and August, the boat ride out is long and open, and seasickness ends more of these trips than weather does.
- Hazard
Hurricane season
1 Jun – 30 NovSeptember and October are the months that matter on this corner of the Yucatan. The ferry from Cancun is the first thing suspended and the last thing restored, so a storm costs you days either side of it. Source ↗
Nearby, and something's on
Within 300 km of Isla Mujeres — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Isla Mujeres?
Isla Mujeres in September — FAQ
- Is September a good time to visit Isla Mujeres?
- September in Isla Mujeres: sweltering, soaked, with clean air — fine if you can take 23 rainy days. It ranks #11 of 12 months for Isla Mujeres on SeasonMap's comfort score (78/100).
- What is the weather like in Isla Mujeres in September?
- In September, Isla Mujeres averages a daily high of 31.5°C and a low of 24.5°C, with about 175 mm of rain over roughly 23.3 rainy days.
- What is the air quality in Isla Mujeres in September?
- Isla Mujeres has a mean US Air Quality Index of about 35 in September.
Other months in Isla Mujeres
Compare Isla Mujeres in September
Warmer or cooler than Isla Mujeres in September
Similar destinations in North America — September
Within 300 km: Cancún's Sea turtle nesting around 1 May – 31 Oct, and Holbox's Whale shark season on 15 May – 17 Sep.