This will depend on the starting temperature or outdoor temperature. The temperature of our saunas increases by approximately 1.5°C every minute. So, if the outdoor temperature is 20°C and you want to reach 80°C, it will take 40 minutes. If the starting temperature is 0°C and you want to reach 80°C, it will take an hour. Please note these are estimated times, and not exact, as your location can also impact the warm up time.