When does a red-eared slider start hibernating?

Red-eared sliders usually enter hibernation in November and wake by late March. As cold-blooded animals, they start at under 13°C. During hibernation keep the environment near 5°C for deep sleep and change water regularly.

Above 15°C they avoid hibernation, which is why many home sliders do not hibernate due to warm rooms; do not let sliders under 5 cm long hibernate.