India in April: Weather, Where to Go, and What to Avoid

• Golden Triangle and Rajasthan — hot, and increasingly uncomfortable for full-day sightseeing.
• Himachal Pradesh and Uttarakhand hill stations — pleasant, and starting their main season.
• Kashmir — a good spring window, greening up before the summer crowds.
• Ladakh — still largely inaccessible; the high passes have not yet opened for the season.
• Kerala and South India — hot and humid ahead of the monsoon.

The hill stations of Himachal Pradesh and Uttarakhand, plus Kashmir, are the better choices now that the plains are heating up. If you must do the Golden Triangle this month, plan sightseeing for early morning and late afternoon.

• Baisakhi — Punjab's spring harvest festival, 13 April (fixed date).
• Ram Navami — marking the birth of Lord Rama (date varies with the lunar calendar).

• A Golden Triangle or Rajasthan-heavy itinerary planned for full midday sightseeing — the heat is a real factor by now.
• Assuming Ladakh is open — the high passes typically open later in the season, not in April.