Pack light, breathable clothing year-round; add a rain layer and waterproof footwear for June-September monsoon, and a warmer layer if visiting north India in winter or hill stations.
Clothing
Lightweight cotton shirts/tops (best for heat and humidity)
Loose trousers or long skirts (modest for temples and comfortable in heat)
Shorts for casual wear (more suitable in big cities/beach areas)
Breathable underwear and socks (quick-dry preferred)
Sleepwear (lightweight and modest)
Light sweater or cardigan (for AC trains, malls, and cooler north India evenings)
Scarf or shawl (useful for sun, dust, and temple coverage)
Rain jacket or compact poncho (Jun-Sep monsoon)
One smarter outfit (for nicer restaurants, business, or ceremonies)
Footwear
Comfortable walking shoes (for long days and uneven sidewalks)
Sandals or slides (easy for hot weather and temple removals)
Closed-toe shoes (better for trains, rural areas, and some sites)
Flip-flops (for hotels, showers, and beach destinations)
Socks that are easy to remove (handy for temples and homes)
Toiletries & Health
Sunscreen SPF 30+ (strong sun in most regions)
Insect repellent with DEET or picaridin (especially evenings and monsoon season)
Hand sanitizer (useful when soap/water are unavailable)
Wet wipes or tissue pack (many public restrooms lack supplies)