Athirapally falls is safe to visit all round d year.. actually post monsoons, it ll be in full glory
Get down at chalakudy n not ers.. closer from there. Many private n govt buses are available
Also visit valparai if u ve enough time.. best part is the journey from athirapally to valparai.. there are a few buses per day which start from chalakudy n go to valparai via athirapally