Like Mike said, the big SXS shoot at HHHSC on June 3-4-5 of 2011 this year. It was a great shoot this year, the rain stayed away. Any later in June and it may get to hot at HHHSC.
August is too hot in Ohio. Also the vendor tents may end up doing what the outdoor stage at the fair did in Indy just the other day, blow down in a summertime thunder storm. Ohio plus August equals big thunder storms. Guns and tents and thunder storms are not a good mix.
Maybe up around the Finger Lakes of New York the weather would be pleasant enough to hold a big SXS shoot in August.
The last weekend of September in Maryland is sometimes to hot to do much shooting. Some years the last weekend of September in Maryland is prime time for the last hurricane of the season.
The third or fourth weekend of May in 2012 would be a good weekend to shoot in Ohio.
Good Shooting To You All, Jent
