June can be a great time to fly to Nadi from Koh Samui with a flight ticket averaging about ฿ 28,949. Cheapflights users have found deals in the month of June for as cheap as ฿ 19,177. The most expensive prices can be found in the month of October.
When travelling, it's generally smart to pack in preparation for rain or any other conditions that may arise. The rainfall in Koh Samui is roughly less than Nadi. You can assume this to be the case over the next 12 days.
Expect the weather to be around 33 °C on average in May. As the temperature peaks, try to get your plans done early, as flight price and availability will have an impact on your travels. The climate in Nadi is generally colder than in Koh Samui.