- During the battle of Gettysburg, Rev. Dr. Michael Jacobs, a math professor had a strong interest in weather and recorded his observations three times a day. These records were published in “Meteorology of the Battle” and give specific details on the weather and the role it may have played in the outcome.
- The biggest impact was heavy rain after the battle, which led to flooding in low-lying areas like Plum Run Creek, causing it to overflow its banks. Those stranded near the floodwaters, reportedly all Confederates, drowned. The rain also impeded the Confederate retreat across the Potomac to the south of the battlefield.
