Weather in Vũng Tàu in September

A hard month. September is a hard month in Vũng Tàu, and worth planning around. You should expect rain on 26 days of the month, which is more days wet than dry.

September ranks 8 of 12 in Vũng Tàu: past the worst of the year but short of January, which is the month to book if the dates are open.

Rain on 26 of the month's 30 days, 7 of them heavy. At that frequency a wet-weather backup is not a contingency, it is the itinerary — book the indoor things first and treat the clear days as the bonus. Natural fibres and a second shirt for the day. At 87% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: 10 days top 30 °C — hot spells arrive, but they break; the day barely swings — 4.7 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest September day reached 32.4 °C and the coldest night fell to 23.5 °C, and the wettest single day dropped 60 mm — roughly 29% of the month's rain in one day.

September is one of the reliable ones — rainfall has stayed between 139 mm and 338 mm across all twenty years, a narrow enough band that the 210 mm average is something you can plan against rather than merely quote.

Wind is light at 10.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity at 87% is the real story though — it is the number that decides how the day feels, not the 29.6 °C.

How September sits in the year

Temperatures hold steady either side: 29.8 °C in August, 29.6 here, 29.6 in October. Nothing about the timing within the month matters much.

Daylight in September

Vũng Tàu sits close enough to the equator that daylight barely moves all year — 12.2 hours in September, against a range of just 1.2 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

Sea temperature

The sea sits at about 28.8 °C in September — warm enough that the water offers no relief from the heat. The sea peaks at 29.9 °C in May and bottoms out at 25.3 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

September in Vũng Tàu versus nearby

If Vũng Tàu is one option among several, the nearby comparison is worth making. Ho Chi Minh City is close enough to be a coin toss — within a degree on temperature, 3 days less rain. Cần Thơ is close enough to be a coin toss — within a degree on temperature, 3 days less rain.

So: September is a compromise. January is 31 points better and is what Vũng Tàu is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Vũng Tàu

See all twelve months in Vũng Tàu, or where else to go in September.