As I've pointed out before, you really don't get much rain in your area. You really have to get over that midnset. By way of comparison, Cincinnati gets 41" on average but we had 73" last year. That's twice your average. But my milk jugs stay out there with no caps, lots of rain and snow and fresh air which I think helps germination and survival. They're also less susceptible to too much heat.
Interesting:
http://www.todayifoundout.com/...
Karen