What September feels like in Cancun
September falls in Cancun's wet season — the rainfall numbers rise clearly above the dry months. Expect proper heat in the afternoon — slow down between noon and four. Nights bring little relief: even the coolest hour of the night stays very warm. The air is muggy, so it feels hotter than the thermometer suggests.
Rain in Cancun in September
Dry days are the exception, with rain on most days. A rainy day brings about 8 mm (0.3 in) on average — steady rain rather than a passing shower. Across the year Cancun averages about 7 mm per rainy day, so September is typical. September is Cancun's wettest month of the year.
Daylight and sunshine in September
Mid-month, Cancun gets 12 h 18 min of daylight, from sunrise near 6:34 am to sunset near 6:52 pm. Days are getting shorter: 35 min less daylight than in mid-August. The sun is out for roughly 85% of those daylight hours, so skies are mostly clear.
How September compares to the rest of the year
Ranked by average high, September comes out as the 3rd warmest month in Cancun. Afternoons run 0.6°C (1.1°F) cooler than in August, with 48 mm more rain. Temperatures keep falling into October. October averages a high of 28.7°C (83.7°F).
Who September suits
- Sightseeing: less ideal — rain falls on more than half the days.
- Parks & outdoor: less ideal — afternoons are too warm to linger outside.
- Beach: less ideal — too many rainy days.
- Museums & indoor: a good choice — with rain on most days, galleries and museums make easy plans.
Tips for visiting Cancun in September
Rain Protection
A compact umbrella and a light waterproof jacket.
Sun Protection
Sunscreen, a hat and sunglasses; light breathable clothes.
Quick questions
How warm is Cancun in September?
Expect around 29.9°C (85.8°F) in the afternoon and 25.7°C (78.3°F) at night, which most visitors would call hot.
Does it rain a lot in Cancun in September?
It does: about 23 rainy days bring roughly 185 mm, so plan some indoor options.
What should I wear in Cancun in September?
The numbers point to rain protection and sun protection. Evenings feel similar to the day, so the same clothes work from morning to night.
Is September or October better for visiting Cancun?
October, narrowly: it ranks #10 of 12 among Cancun's months, against #12 for the other. October is cooler and has fewer rainy days.