According to
http://www.fly4less2india.com/ here are the best times to buy tickets to India.
Following is a guide of travel pattern to India and suggested time to book.
Availability for different airlines can vary.
USA to India Travel pattern What's happening Suggest booking
------------ -------------- ---------------- ---------------
01Jan - 15Jan =========== Overspill from winter holidays by mid Nov
16Jan - 31Jan ======== Slowing down by mid Dec
01Feb - 15Apr ====== Slow Jan onwards
16Apr - 10May ========= Pre summer travel picks up Feb onwards
11May - 31May ========== Start of Summer Holiday rush Feb onwards
01Jun - 10Jun ============ Summer rush picks up before Mar end
11Jun - 15Jul ============ Peak summer travel before Mar end
16Jul - 31Jul ========== Continuing Apr onwards
01Aug - 15Aug ======= Slowing down May onwards
16Aug - 31Aug ===== Slow Jun onwards
01Sep - 15Sep === Low fare rush May onwards
16Sep - 10Oct ===== Slow Jun onwards
11Oct - 15Nov ========== Diwali travel Jul onwards
16Nov - 30Nov ============ Thanksgiving Holidays travel Jul onwards
01Dec - 10Dec ============== Low fare rush before mid Jun
11Dec - 15Dec ============== Winter Holidays rush begins before mid Jun
16Dec - 24Dec ========= Peak winter travel before mid Jun
25Dec - 31Dec ===== Low fare rush before Jun end
India to USA Travel pattern What's happening Suggest booking
------------ -------------- ---------------- ---------------
20Aug - 08Sep ============= Peak summer return travel by mid Mar
20Dec - 10Jan ============= Peak winter return travel before mid Jun