The most popular airports for THAI Smile are Bangkok Suvarnabhumi, Khon Kaen, and Chiang Rai according to our data. Flights to or from any of these airports should be available via THAI Smile year-round.
The cheapest domestic THAI Smile flight is flying Bangkok Suvarnabhumi to Udon Thani, which is HK$616. This round-trip flight has 0 stops. For a one-way domestic THAI Smile flight, the cheapest route is Chiang Rai to Bangkok Suvarnabhumi (0 stops) for HK$257.
Based on current airline data, it looks like THAI Smile has around 14 flights from Hong Kong Intl per week. Keep in mind that this could change based on demand and cancellations.