The best months in Coorg are October to March, after the monsoon has cleared but before the summer heat creeps up from the plains. Days are warm and clear, nights cool enough to want a sweater, and the coffee estates are at their most photogenic.
Monsoon (June to September) drenches the district — Coorg is one of the wetter parts of India. Some travellers love it for the empty roads, raging waterfalls, and electric-green countryside; others find that nothing dries and the leeches are intolerable. April and May are pre-monsoon: hot, humid, and best avoided.
The big local event is the Kaveri Sankramana in mid-October, when pilgrims gather at Talakaveri to bottle the holy water at the moment the spring is said to rise. Madikeri is busy at New Year and during the Indian winter school holidays.