In September 2024, Hurricane Helene struck the Florida Gulf Coast with heavy rain and a large storm surge, severely impacting the low-lying, limestone-based coastline around Apalachee Bay. To understand how this extreme storm affected local groundwater, we collected water samples over several months from both deep springs and shallow groundwater near the beach and estuary. We found that spring water, which comes from the deep Floridan aquifer, returned to normal conditions within a month because of the typical high transmissivity of karstic aquifer. However, shallow groundwater responded differently depending on the type of soil and rock in the area. The sandy beach aquifer briefly showed signs of oxygen and high nitrate after the storm but gradually returned to pre-storm conditions. Meanwhile, the estuarine aquifer, which contains more clay, held onto salty water and other storm-related changes for over eight months. These results show that different parts of the coastal groundwater system respond in very different ways to extreme weather. As strong storms become more frequent with climate change, understanding how each local aquifer behaves will be important for protecting water resources in coastal areas.