I have also had this occur. It has happened at various times of day and not daily. Mine will go up so fast and gets up to 177/90 to 190/101 etc. I have caught it at the 150/90 and 161/90 and took the medicine that my doctor told me to take if it gets 150/90 or above.(Clonidine 0.1mg) The only thing is that it makes me feel terrible, it does bring the bp down but it takes me two days to start to feel better. I have only been on medicine for 4 weeks since I was just recently diagnosed and the doctors told me this is not unusual until my bp gets adjusted which takes 6 weeks or more. I start to feel a little normal until the bp spikes upward then I feel I took a few steps backwards. I had the spike happen yesterday at 8:30 am ( I take my bp meds at 6:00am) took he clonidine and had to leave work because of how it makes me feel. I just hope I get normal soon.