7 months head circumference

This must have been asked a ton but I was wondering what your baby's head circumference is. My 7-month old's HC was 42.5 at his 6-month appointment and I'm due for his next check-up and I measured it at 43cm only (me at home, not the pediatrician). His pediatrician is 250 miles away from here (we are temporarily living far away because my husband has a training course for his job) so I can't just drop by whenever. The reason I'm asking is because since 2-3 days, I can feel like a raised ridge across his head (from ear to ear, in front of  the fontanelle as seen from the front).
On another note, who can tell me when the fontanelles usually (are allowed to) close?
Thanks for the help and info!