Physiology General 08fb0113 LH peak occurs how many hours before ovulation ? A 36-48 hrs. B 12-24 hrs. C 48-72 hrs. D 72-96 hrs. High-Yield Explanation Ans.B.)12-24 hours Ovulation occurs 34 to 36 hours after the onset of the LH surge and about 10 to 12 hours after the LH peak.