Comment by lkbm
I mostly see 25 mph for school zones, though I'm in NC. Checking California, it sounds like 25 is standard there as well.[0] Some will drop to 15, but 25 is the norm as far as I can find.
[0] https://www.dmv.ca.gov/portal/handbook/california-driver-han...
I've lived all over California and I agree that 25mph is the norm here.
Edit: However, elsewhere in the thread someone linked this Streetview image that shoes that this particular school zone is 15mph: https://maps.app.goo.gl/7PcB2zskuKyYB56W8?g_st=ac