Off the Radar: Gettysburg's Weather Secrets: Why Every Observation Matters

Episode Release Date: July 8, 2025
Host: Emily Gracey
Guest: Dr. John Neese
Co-Author Mentioned: Jeff Harding

Introduction

In the episode titled "Gettysburg's Weather Secrets: Why Every Observation Matters," National Weather Desk Meteorologist Emily Gracey delves into the profound impact of weather on one of the most pivotal battles in American history—the Battle of Gettysburg. Joined by Dr. John Neese, co-author of the insightful book "The Weather Gods Curse the Gettysburg Campaign," the discussion unravels how meteorological data from the 19th century provides an unprecedented window into the challenges faced by both Union and Confederate forces.

Background: Weather’s Role in the Battle of Gettysburg

The episode opens with a vivid portrayal of the harsh weather conditions during the Gettysburg Campaign in 1863. Emily Gracey sets the scene:

[00:00] Emily Gracey: "Picture this. The year is 1863 and Union forces are marching toward Pennsylvania unprepared for the scorching heat that would SAP their strength before they even reach the battlefield."

Dr. John Neese elaborates on the unforeseen natural forces that both armies contended with:

[00:47] Dr. John Neese: "I'm thinking to myself, well, this is fabulous. We can take the best technology available, bring in what few observations they had, you can rebuild sort of a best guess weather map."

Uncovering Historical Weather Data

Dr. Neese and his co-author, Jeff Harding, unearthed a treasure trove of weather data that had previously been overlooked. The data primarily originated from the Naval Observatory in Washington, D.C., which provided high-quality, consistent measurements even during the Civil War era.

[08:21] Dr. John Neese: "You know what? You nailed it. I mean, I got some Civil War maps that Jeff helped me locate that showed where the troops were every day between June 3 and July 14. I took those maps to my local printer and I blew them up, like, 3ft by 2ft. And then I just started plotting soldier comments and weather data on these maps."

Using NOAA’s computer program designed to reconstruct historical weather conditions, Dr. Neese was able to create detailed weather maps for the Gettysburg period, offering a forensic analysis of how weather influenced military decisions and the battle's outcome.

Impact of Weather on the Gettysburg Campaign

The weather had a multifaceted impact on the campaign:

1. Heat Wave (June 15-18, 1863):

   • Dr. John Neese explains the severity of the heat wave:

     [15:54] Dr. John Neese: "We make the argument to answer your question, Reader's Digest version is it was the period from the 15th to the 18th where sunstroke was rampant."

   • The extreme heat, with temperatures and dew points soaring, led to hundreds of soldiers suffering from sunstroke, particularly affecting the Union army who had to march under these harsh conditions.

2. July 3, 1863 – Pickett’s Charge:

   • On the climactic third day of the battle, the heat index reached 100°F or higher, exacerbating the soldiers' exhaustion:

     [13:07] Dr. John Neese: "The heat index was 100 or higher. And of course, a lot of the soldiers were laying in the sun for three hours."

   • This intense heat played a critical role in the failure of Pickett’s Charge, the Confederate assault aimed at breaking the Union lines.

3. Post-Battle Rainfall and River Flooding:

   • Following the battle, unexpected heavy rainfall caused rivers to flood, delaying the Confederate retreat:

     [14:37] Dr. John Neese: "But when the Confederates tried to retreat back to Williamsport, Maryland, a few of them got across on July 4th and July 5th. But then the river got too high."

   • The rising Potomac River, reaching heights of 15 to 20 feet, effectively trapped Lee’s army, preventing a swift retreat and prolonging the campaign’s end until July 14, 1863.

Personal Stories and Soldier Accounts

Jeff Harding contributes a rich tapestry of personal anecdotes that bring the historical data to life. These stories include:

• Acts of Heroism:

  [12:02] Jeff Harding: "About the one Medal of Honor recipient who received the medal because he saved a soldier who had sunstroke and he stayed with this soldier even under enemy fire and got him to safety."

• Daily Struggles:

  [12:02] Jeff Harding: "We have a story in the book about a gentleman who owned a vineyard in Front Royal, Virginia, and his son was killed in the war mere miles from their home."

• Dedication of Observers:

  [12:02] Jeff Harding: "We have some vignettes about some of the observers, everyday people who just decided, yeah, I'll be an observer. I'll be an observer for the Smithsonian Institution."

These narratives underscore the human element of the campaign, highlighting how weather conditions directly affected individual soldiers and their families.

Research Surprises and Challenges

Both Dr. Neese and Jeff Harding encountered unexpected findings during their research:

• Lack of Previous Meteorological Analysis:

  [20:05] Jeff Harding: "I was kind of surprised that no one had ever used this rich data set from the Naval observatory in Washington D.C. and applied it to the Civil War."

• Sparse Data in Key Regions:

  [20:25] Dr. John Neese: "There really were no observers in Virginia."

The scarcity of weather observations in certain areas posed significant challenges, yet the high-quality data from the Naval Observatory provided a solid foundation for their analysis.

Conclusions and Historical Implications

The episode concludes with reflections on how weather data can reshape our understanding of historical events:

[18:34] Dr. John Neese: "If they had modern weather forecasts, even reasonably accurate forecasts, and that had been worked into the planning, there's absolutely no doubt that the Union could have conserved some energy during that heat wave."

This statement invites listeners to ponder the profound influence that accurate weather forecasting could have had on the strategies and outcomes of historical battles.

Book Release and Upcoming Events

Dr. Neese announces the official release of "The Weather Gods Curse the Gettysburg Campaign" on June 10th, along with upcoming speaking engagements in Gettysburg:

[21:48] Dr. John Neese: "I feel very blessed to have been invited with my co author Jeffrey Harding to speak in Gettysburg on July 5th this year in something called the Sacred Trust."

Listeners are encouraged to attend these events for a deeper exploration of the interplay between weather and military strategy during the Gettysburg Campaign.

Closing Remarks

Emily Gracey wraps up the episode by highlighting the importance of meticulous weather observations:

[22:49] Jeff Harding: "John Neese, thank you so much for your time today. Once again, this was a great learning experience. This book is great. I encourage everybody to get it."

She also teases the next episode, which will focus on sharks, ensuring listeners stay engaged with future content.

Key Takeaways:

• Weather significantly influenced the strategies and outcomes of the Gettysburg Campaign.
• Historical weather data provides valuable insights into past events, enriching our understanding of history.
• Modern meteorological tools can reconstruct historical weather patterns, offering a forensic lens into the past.
• Human stories intertwined with weather conditions highlight the resilience and struggles of soldiers during the Civil War.

This episode serves as a compelling reminder of the intricate relationship between weather and human endeavors, particularly in the context of war, and underscores the indispensable role of accurate weather observation in both historical and modern settings.