The D-Day Forecast: Operation Overlord

June 04, 2025

The Mission: Operation Overlord

Operation Overlord, also known as the D-Day invasion, was the Allied invasion of France on June 6, 1944, aimed at liberating Western Europe. The operation consisted of a monumental amphibious assault on the beaches of Normandy, France, engaging land, sea, and air forces in the largest invasion of its kind.

Why Weather Was Critical

For the Allied invasion to succeed, General Eisenhower, the Supreme Commander of the Allied Forces, required specific conditions: a full moon, low tide, minimal cloud cover, gentle winds, and calm seas. In June 1944, the perfect combination of a full moon and low tide was forecasted to occur on the 5th, 6th, and 7th.

A Last-Minute Change That Saved the Day

The weather forecast played a vital role in deciding the date of the invasion, which was initially set for June 5th. Weather observations of a falling barometer made in western Ireland on June 3rd warned the Allies of an impending storm, prompting them to postpone. Did this weather warning change the course of history? The meteorology team lead by James Stagg, anticipated improvement in weather conditions between 5-6th June and the new date was set. The conditions on the morning of June 6th was sufficient for the invasion to move forward, and the rest, as they say, is history.

Commemorate History in Your Home

To commemorate one of the most significant forecasts in recent history, the Metcheck ‘Operation Overlord’ offers a comprehensive forecast of atmospheric pressure, temperature, humidity levels, tidal patterns, and lunar phases.