Mine rises also not daily and at various times morning, afternoon and evening. I tried the splitting of meds but it did not help. Since I am newly diagnosed and only been on meds for 4 weeks the drs said it is not unusual for this to happen until my bp gets adjusted and it takes 6 or so weeks on medicine. When mine goes up it just very high very quickly and I have to take clonidine to bring it down if it gets to 150/90 or above. The clonidine however, really makes me feel awful even thought it brings down the pb. My body just does not like this medicine for some reason. Have you been on medicine for bp a long time?