You were wondering about the weather during the battle. The data I have is from Charles Teague's "Gettysburg by the Numbers", which I believe he based on the observations of Professor Jacobs (who taught at the local college we now know as Gettysburg College), on July 1 it was already 72 degrees at 7 a.m.; 76 at 2:00 p.m. and 74 at 9:00 p.m. The sky was cloud covered much of the day, and only a "gentle breeze". [As someone who has lived most of his life in Pennsylvania, the temperature at 72 that early suggests that it was very humid.] On July 2, it was 74 degrees at 7:00 a.m., 81 at 2:00 p.m., and 76 at 9:00 p.m. The sky was mostly cloud covered early in the day but cleared to be about 3/10 covered by 2:00 p.m. On July 3, it was 73 degrees at 7:00 a.m., 87 degree at 2:00 p.m. and 76 at 9:00 p.m. Only about 4/10 of the sky was cloud covered in the afternoon, but large thunder clouds were seen, and at night 7/10 covered with cumulus. Wind very gentle. July 4 was a rainy day.
Bear in mind that the Union soldiers are dressed in dark blue, long sleeve woolen jackets.
Most people I know, including myself, get quite emotional there in their own ways. Its hard not to in light of what happened there in 1863. I say let 'er rip! 
Bringing the