Debconf18 will be held at the height of typhoon season in typhoon alley: Taiwan. Therefore,
Be sure all indoor events can still be held according to schedule even if a national holiday is declared and all building staff are sent home, etc. Check with the facilities on what contingency plans and legal ramifications etc. Do it now and not only if a typhoon is declared. Be sure all outdoor events have a backup plan B to become an alternative indoor event. And/or one indoor event day X that can be swapped with outdoor event day Y (separated by several days), just in case.