Quick Summary: Con Dao weather stays warm year-round, with a calmer dry season (roughly December–April) and a windier, wetter season (May–November). The best time to visit is December to April, when seas are at their calmest for diving and beach time. May is the warmest month at 28.7°C, and the island logs its highest rain days — 26 — in October.
Far more remote than Phu Quoc, this cluster of granite islands sits alone in open water off Vietnam’s southern coast, so its weather is shaped almost entirely by wind and sea state rather than the land features that steer weather on the mainland. Rugged cliffs and dense forest cover much of the archipelago, giving Con Dao’s weather a wilder, more exposed feel than delta towns just across the water.
Con Dao Weather at a Glance
- Con Dao weather is warmest from May through August, averaging 27.6–28.7°C, and coolest in January–February at 25.1°C.
- Dry season runs roughly December–April, with rain days as low as 1 in February.
- Wet season runs May–November, with rain days peaking at 26 in October.
- Con Dao logs around 190 rain days a year, with wind and sea swell — not just rainfall — playing a big role in deciding the best time to visit.
Best Time to Visit
December through April brings Con Dao’s calmest seas and clearest skies, with rain days as low as 1–6 a month and temperatures a mild 25.1–27.9°C — ideal for diving, hiking and beach time on this quieter alternative to Phu Quoc. Late in the wet season, from September to December, stronger winds can make crossings and water sports choppier, even on days without much rain.
Weather by Seasons
Dry Season (December–April): Temperatures run 25.1–27.9°C, with rain days climbing from a yearly low of 1 in February to 6 by April. Seas are typically at their calmest during this stretch, and it’s the most reliable window for boat trips around the archipelago.
Wet Season (May–November): Average temperatures stay warm at 27–28.7°C, with rain days ranging 20–26 per month and peaking in October. Per weather data from Kupi.com’s Con Dao weather page, wind and swell tend to build toward the end of this period, so travelers aiming for calm water should lean toward the earlier wet-season months if visiting outside the dry season.
Daily Weather & Humidity Insights
As an island archipelago, Con Dao’s humidity stays fairly high year-round — generally 70–80%, with less of a sharp dry-season drop than mainland towns see. The day-night temperature gap is narrower here too, typically around 5–6°C, since surrounding open water keeps both daytime highs and nighttime lows fairly steady. Sea breezes help the heat feel more manageable than at inland destinations, even in the warmer months.
What to Wear and Pack
- Swimwear, reef-safe sunscreen and light clothing for beach and boat days.
- A windbreaker for breezy stretches, especially September through December.
- Sturdy shoes for hiking trails through Con Dao National Park’s forest.
- A rain jacket for wet-season showers, May through November.
- A dry bag for boat trips, since spray and sudden showers are both common.
Essential Local Tips
- Book inter-island boat trips for the morning, when seas are typically calmer before any afternoon wind picks up.
- From September to December, check conditions before planning water activities, since stronger winds and swell can appear even without heavy rain.
- The clearest snorkeling visibility tends to fall in the dry season, when calmer seas keep sediment from clouding the water near the reefs. See more things to do in our our full Con Dao travel guide.
