Luckily for traveling history buffs, the weather in Gettysburg is pretty predictable, even during the peak days of summer. The average temperature maxes out at around 85 degrees Fahrenheit. That said, if you’re used to dry heat, the humidity on the Gettysburg Battlefield is something to keep in mind. The high moisture worsens the temperature thanks to all the rain in this region. Gettysburg sees about nine rainy days in May, June, and July and 6-7 rainy days in August and September.
Are you traveling in the winter? January and February occasionally see a few days of heavy snowfall, but the park service is vigilant about cleaning the roads quickly and early.

Luckily, you’ll tour Gettysburg Battlefield from the comfort of your car so you can adjust the AC and heat as needed! The weather won’t make much difference in your visit, not as it did during the actual battle.
What was the weather like in Gettysburg during the battle?
Some historians think that the combination of heat and humidity during the three-day Battle of Gettysburg changed the course of the battle entirely.
During those first days of July 1863, temperatures ranged from the mid to high 80s. Doesn’t sound that bad? The soldiers on both sides had to wear heavy wool uniforms while running, fighting, and carrying heavy equipment. And that’s not even considering the humidity, which would have been around a sticky 60%! This means that even soldiers hunkered down in shady spots couldn’t find much respite from the heat. Gettysburg was a sweaty and probably exceptionally stinky battle, attributed to the weather.
So, how does the weather at Gettysburg change the outcome of the battle? Well, let’s consider one particular example to understand better: Pickett’s Charge. Major General George Pickett led a massive, 12,500-man charge toward heavily fortified Union lines in Confederate General Robert E Lee’s direction. This last-ditch effort attack occurred at the hottest point of the hottest day of the battle: 2 pm on July 3rd. The temperature had just cracked 87 degrees. The sun was directly overhead, beating down on the wool-clad attackers.
Now, the charge would always be a long shot, but Lee’s men had just spent the last two days charging up hills in the stifling heat. By the time he ordered this charge, they had just about run out of gas. On the other hand, the Union men had the luxury of staying put. As the defenders, they didn’t need to rush across vast fields or sprint uphill. In a battle like this, an advantage as slight as that can make all the difference in the world. The Union repelled the Confederate attack at the “High Water Mark.” Check out this historic spot during your visit with this Gettysburg self-guided driving audio tour.
What might have happened if the weather had been a little cooler? Sometimes, maybe all it takes to change the history of a nation is a few degrees Fahrenheit! Learn all about the effect of Gettysburg on the Civil War with this self-guided driving tour during your visit.