Here in southern California we get another layer of pricing in addition to time of year/time of day - we have usage tiers and as you use more power up to certain milestones each kw/h after that becomes more expensive. My electricity bill takes complex math to figure out.
Not just a California thing, seen that all over.
Where I'm at now though is a bit odd, in that on my non-Summer base rate the lower tiers are HIGHER in price - I've seen your way a lot more often.