On the USDA cold hardiness map, we are in zone 7A. But temps vary a lot. For example, the average daily low for December was 8 degrees F below the previous December. Maybe they should call us zone 7 +/- 2.
The kujaku spawned on 5/9 and the eggs hatched on 5/12. I feel fortunate because that's kind of early for us. The first week of June seems to be the most typical spawning time, though we've seen accidental spawns happen anywhere from late March to early July. They started spawning at 68 F water temperature just before it really cooled off. By the time they were done in the morning, the water was 65 F. So I think I almost had to wait another couple of weeks.