Weather in Qui Nhon in September

Shoulder season. September sits in between. You will get good days and you will lose some. You should expect rain on 23 days of the month, which is more days wet than dry.

September ranks 11 of 12 — near the bottom of Qui Nhon's year. February is the month that works, and the swing between the two is 48 points, which is a different holiday rather than a slightly better one.

Rain on 23 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. Pack for 30 °C days and 27.6 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 14 days top 30 °C — hot spells arrive, but they break; the day barely swings — 2.4 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest September day reached 33.3 °C and the coldest night fell to 25.5 °C, and the wettest single day dropped 87 mm — roughly 37% of the month's rain in one day.

September is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest September on record still delivered 417 mm against 74 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 238 mm average is a reasonable planning figure, not a promise.

Wind is light at 12.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 81%, high enough to notice on the warm days without dominating them.

How September sits in the year

Temperatures hold steady either side: 31.1 °C in August, 30 here, 28.3 in October. Nothing about the timing within the month matters much. Rain has already shifted: 5 days more than August had.

Daylight in September

Qui Nhon sits close enough to the equator that daylight barely moves all year — 12.2 hours in September, against a range of just 1.6 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

Sea temperature

The sea sits at about 29.3 °C in September — warm enough that the water offers no relief from the heat. The sea peaks at 29.5 °C in June and bottoms out at 25 °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 Qui Nhon versus nearby

If Qui Nhon is one option among several, the nearby comparison is worth making. Nha Trang is close enough to be a coin toss — within a degree on temperature, 3 days more rain. Hoi An is close enough to be a coin toss — within a degree on temperature, 1 day less rain.

So: September is a compromise. February is 44 points better and is what Qui Nhon 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 Qui Nhon

See all twelve months in Qui Nhon, or where else to go in September.