Ok,
Here are some info...
As you could see, this year around the time i'm thinking of, it never froze. But this is the weather at Robinsville... higher altitude might be little different.
But overall, we should be looking at highs in the 70s and low in the 40s F.
Should be a great weather for rotaries
PS.. also month of April is statistically least amounts of rain. But that being said, only 2 DGRR rained but only on friday and part saturday. Usually we have a beautiful weather at least one day out of 3.