Last at KOS was this, also in rain (from Airline Safety Network):
Status: Final
Date: 21 NOV 1990
Time: 11:15 UTC
Type: de Havilland Canada DHC-8-103
Operator: Bangkok Airways
Crew: Fatalities: 5 / Occupants: 5
Passengers: Fatalities: 33 / Occupants: 33
Total: Fatalities: 38 / Occupants: 38
Airplane damage: Written off
Location: 5 km (3.1 mls) SW of Koh Samui Airport (USM) (Thailand) show on map
ASN Aircraft accident de Havilland Canada DHC-8-103 HS-SKI Koh Samui Airport (USM)