Do koi fish die with rainwater?

Koi fish generally do not die from rainwater itself, as they can adapt to various water conditions. However, heavy rain can lead to changes in water quality, such as increased acidity or dilution of beneficial nutrients, which may stress the fish. Additionally, if rainwater runoff contains pollutants or chemicals, it could harm the koi. It's essential to monitor water quality after significant rainfall to ensure a healthy environment for the fish.