Red: Flown when conditions are determined to be out of the ordinary, such as the presence of strong wind, strong current or large surf. Adult swimmers should stay in water no more than waist deep and non-swimmers and children should be kept along the surf line.

In Galveston, a Red Flag Warning is a critical safety alert issued by the National Weather Service and local beach patrols indicating hazardous weather and sea conditions. When the red flags are flying at the beach, it signifies a high risk of strong rip currents and dangerous surf. Swimming is strongly discouraged, even for experienced swimmers, as the underlying currents can be powerful enough to pull a person away from the shore rapidly. Beyond the water, a Red Flag Warning also alerts the community to a high risk of wildfires due to a combination of high winds, low humidity, and dry vegetation. In 2026, Galveston authorities use a color-coded flag system on all lifeguard towers to communicate these risks in real-time. If you see a red flag, it is best to stay in "waist-deep" water at most, or better yet, stay on the sand entirely, as the "invisible" dangers of the Gulf of Mexico are at their most volatile during these periods.