A frost advisory is issued when temperatures are expected to fall between 33°F and 36°F under clear skies and calm winds (5 mph or less). These conditions allow heat to escape from the ground, creating localized frost even if the air temperature remains above freezing. Sensitive plants like tomatoes, peppers, and flowers may suffer minor damage. To protect them, gardeners should cover plants with sheets or row covers before sunset and water the soil to retain heat. Timing is crucial—cover plants while the ground is still warm in the late afternoon.