The short answer
October to March suits most of the country: the plains are cool and dry, Rajasthan is at its best, and the south is comfortable. April to June is Himalayan season — the high passes open and the plains become unbearable. July to September is monsoon, which is glorious in Kerala and the Northeast and difficult almost everywhere else.
Month by month
| Month | At its best | Avoid |
|---|---|---|
| January | Rajasthan, Kerala, Goa, Tamil Nadu | High Himalaya (snowbound) |
| February | Rajasthan, Karnataka, Kerala, Varanasi | Nothing much — the sweet spot |
| March | North India, Hampi, Rann of Kutch | Plains after mid-March get hot |
| April | Himachal, Uttarakhand foothills | Rajasthan, Delhi, Agra (heat) |
| May | Ladakh (opening), Sikkim, hill stations | The entire plains belt |
| June | Ladakh, Spiti, Kashmir | Everywhere below 1,500m |
| July | Spiti, Ladakh, Valley of Flowers | Coastal roads, Northeast landslides |
| August | Ladakh, Kerala monsoon ayurveda | Himalayan road travel after heavy rain |
| September | Meghalaya waterfalls, Ladakh | Tail-end monsoon on the west coast |
| October | Almost everywhere — festival season | Very little |
| November | Rajasthan, Varanasi, Kerala, Goa | High passes closing |
| December | Kerala, Goa, Tamil Nadu, Rajasthan | North Indian fog delays flights and trains |
Festivals worth planning around
- Holi (Feb–Mar) — colour festival, best experienced in Rajasthan or Vrindavan with a local host.
- Diwali (Oct–Nov) — lamps and fireworks nationwide; book accommodation months ahead.
- Pushkar Camel Fair (Nov) — Rajasthan's most photographed gathering.
- Onam (Aug–Sep) — Kerala's harvest festival, with snake-boat races.
- Hornbill Festival (Dec) — Nagaland, the Northeast's cultural showcase.
Fog, heat and monsoon in practice
- Late December and January fog delays northern flights and trains — never plan a same-day international connection.
- Above 40°C, sightseeing has to be dawn-and-dusk only. Plan hill states instead.
- Monsoon travel is fine with flexibility; it is not fine with tight, non-refundable connections in the mountains.