Con Dao (Con Son) weather in September
September in Con Dao: hot, soaked, with clean air — a gamble, with 25 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#11 of 12 months in Con Dao · #1166 of 1413 destinations to visit in September · comfort 58/100 (tier D)
- Days
- 30°C
- Nights
- 26°C
- Wet days
- 25
- Sun
- 8.8 h
- Humidity
- 83%
- Daylight
- 12 h
Traveller notes on Con Dao in September
Con Đảo's forum places September inside southern Vietnam's June-through-October monsoon window, but posters were clear it's rarely a washout - the typical pattern is an hour or so of rain that clears back to sun, with some visitors reporting genuinely sunny, hot days and rain arriving mainly late in the evening or overnight. Mainland weather forecasts were repeatedly called unreliable for the island specifically, so posters recommended just watching the sky rather than trusting an app. Flexible plans matter more than picking an exact date within the month.
Other months in Con Dao
Forum posters consistently name March among the best months here, with sunny, warm weather and calm, clear seas typical this time of year - part of a broader dry season posters place roughly October through March for southern Vietnam generally, though some extend Con Dao's own good-weather window all the way to December. Posters are clear Con Dao runs its own genuine microclimate distinct from the mainland: forecasts based on general southern Vietnam conditions are often wrong for the island specifically, so posters recommend treating mainland weather apps as unreliable and instead checking conditions once actually on Con Dao or close to departure.
Add your own note from Con Dao's card on the map.
Con Dao climate normals — September
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Con Dao 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.
Peak crowdsNational Day, Summer break in Vietnam, school holidays in 3 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Con Dao'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).
Toughest weatherCon Dao's weather peaks February–April, best around March.
Best weatherFair weatherToughest weather
What's on in Con Dao in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Nature
Sea turtle nesting
15 Apr – 31 Oct · usuallyBook earlyGreen turtles come ashore on Bay Canh and the smaller islets, most of them between May and October. The national park runs overnight ranger trips and hatchling releases, and the places on them are limited. Source ↗
- Holiday
National Day
30 Aug – 3 Sep · usuallyNational holidayCrowdedBook earlyNational Day on 2 September comes with at least two days off, usually joined to a weekend, and is a domestic travel peak. Flights and buses sell out, hotels fill with Vietnamese families, and streets are hung with red flags. Source ↗
- Season
Wet season
MonsoonRisk25 rainy days and about 329 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
Nearby, and something's on
Within 300 km of Con Dao — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Con Dao?
Con Dao in September — FAQ
- Is September a good time to visit Con Dao?
- September in Con Dao: hot, soaked, with clean air — a gamble, with 25 rainy days. It ranks #11 of 12 months for Con Dao on SeasonMap's comfort score (58/100).
- What is the weather like in Con Dao in September?
- In September, Con Dao averages a daily high of 30°C and a low of 25.5°C, with about 329 mm of rain over roughly 25.3 rainy days.
- What is the air quality in Con Dao in September?
- Con Dao has a mean US Air Quality Index of about 42 in September.
Within 300 km: Ho Chi Minh City's Mid-Autumn Festival on 25 Sep.