Con Dao’s weather is temperate year round, with two seasons - Dry and Tropical. With over 80% of the island covered in rain forest, regular rainfall is around two meters each year, coming in short and hard bursts, as is typical for tropical climbs, so most of the day is still fine. Humidity averages around 80 - 90% so light comfortable clothing is recommended, but don't forget hats and strong sun lotion as you are only eight degrees from the equator. Although the warmest times of the year are typically June, July and August, with temperatures up to 99F (37C), onshore breezes make it feel cooler. March, April and May have less wind, with an average temperature around 91F (33C). Cooler times of year are from September through January, with temperatures around 82F (28C).
One of the good things about observing wildlife and nature as a whole is its unpredictability, as you never know precisely what you are going to see. Due to this, from year to year, there may be small variations in the timings of naturally occurring events. The dates given here are based on historical patterns and experiences.
Green Turtle Nesting Season
Mid-May to late-September - Officially running from May to October, but perhaps more accurately, from late-May to early-October. There are some thirteen beaches around the islands where Green Turtles come to nest, but only one beach has night time access. Trips depart at night by speedboat to Bay Canh Island where, with your guide, you wait patiently at the Ranger Station. When a female turtle comes to nest the local rangers will guide you to the nest site where you can watch the female as she meticulously lays and covers her eggs. You can then help the rangers collect the eggs and transplant them to a nearby hatchery area. Coming into August it is common to see the hatchlings coming out of the ground and you can assist in releasing them.
Turtle Hatching Season
Mid-August to early-December - If you’re not a night person, then you can join a trip to release baby turtles from Bay Canh Island Turtle Sanctuary. Trips depart from the resort in the early morning, by speedboat. On Bay Canh you'll be shown around the hatchery area where the life cycle of the turtles will be explained. You'll then be given an opportunity to hold the young ones before heading down to the beach and releasing them as they start their life's journey. If you are quick enough you can even go into the water and swim with them.
February – July
Scuba Diving and Snorkeling - The waters around Con Dao are at their clearest during this time with visibility averaging around 70 to 100 feet (20 to 30 meters); with conditions are at their best - little wind, low tidal movement and access to Vietnam's only underwater ship wreck. There is diving available for all competence levels and also the possibility to become certified divers for those wishing to learn.
February - November
Sailing - Winds prevailing from the West and South make great sailing and windsurfing conditions during this time. During December and January, sailing is not possible due to high wind speeds, but sailing and windsurfing activities resume in February.