Chikkmangaluru, Coorg , Pondicherry, Mahabalipuram, Udupi, Mangalore and Murdeshwara. You can refer blogs in my profile for more information on any mentioned places
You may consider wayanad, coorg and bekal.. this triangle is 2 hrs by road..from each other.. the closest airport from bekal is Mangalore and from wayanad is Kozhikode
August can actually be quite a nice month to visit North India. It isn't extremely hot thanks to the rains, there are off-season discounts for most accommodations and services, fewer tourists or crowds, and the pretty lush countryside.