Keep Apple Watch within acceptable operating temperatures

Find out about suitable operating conditions for Apple Watch, and get tips for maintaining those temperatures and handling your device safely.

Find recommended temperatures and conditions below for most Apple Watch models or for Apple Watch Ultra. Apple Watch Ultra is designed for use in conditions and situations beyond what's recommended for other Apple Watch models.

Recommended conditions for using and storing most Apple Watch models

Apple Watch is designed to work best in ambient temperatures between 0° and 35°C (32° to 95°F).

You can store your Apple Watch in ambient temperatures between -20° and 45°C (-4° and 113°F).

Recommended conditions for using and storing Apple Watch Ultra

Your Apple Watch Ultra works best in the following conditions:

  • Ambient temperature while you're wearing Apple Watch Ultra: -20° to 55°C (-4° to 130°F)
  • Ambient temperature while Apple Watch Ultra is charging: 0° to 35°C (32° to 95°F)
  • Ambient temperature when Apple Watch Ultra is being stored: -20° to 45°C (-4° to 113°F)
  • Water temperature during underwater activities with Apple Watch Ultra: 0° to 40°C (32° to 104°F)
  • Relative humidity: 5% to 90%, non-condensing

Ambient temperature and other conditions can affect some features on Apple Watch Ultra and other Apple Watch models. For example, your battery may not last as long in cold temperatures. The ECG app is only accurate when used in ambient temperatures from 0° to 35°C (32° to 95°F). Heart rate measurements can be less accurate in low ambient temperatures. And in very low ambient temperatures, or in conditions where the temperature changes rapidly, the touch screen on your Apple Watch may not respond as expected.

Apple Watch temperature management

Apple Watch shouldn't sit unattended in direct sun for long periods or be left in places such as a car on hot days. Storing and using your device outside the recommended temperature range could shorten its battery life or cause other damage.

If necessary, Apple Watch will regulate its internal temperature. If this happens, you may notice:

  • Charging times may increase or charging may stop.
  • The display may dim.
  • Data transfers could pause or slow down.
  • Apps may close.
  • On GPS + Cellular models of Apple Watch, you may not have a mobile data connection or you may not be able to make or receive calls. When this happens, the mobile data button in Control Centre will appear red. Normal mobile functionality will resume after Apple Watch has cooled down. However, you can still make emergency calls.


Watch face showing the thermometer icon and the time.

If your Apple Watch gets too hot

If your Apple Watch experiences above-normal temperatures, it will only display a red thermometer and the time. Here's what to do:

  1. If you're wearing your device, remove it from your wrist. If your Apple Watch is in the process of charging, remove it from its charger. Your watch will turn off a few seconds after displaying the thermometer. If you leave your watch on the charger, your watch won't turn off. If you try to turn your watch back on, the red thermometer will appear again. 
  2. Move your Apple Watch to a cooler place and let it cool down before putting it back on or continuing to charge it. When your watch has cooled down, it will turn back on.
  3. If you're making mobile calls on a GPS + Cellular model of Apple Watch in an area with a weak mobile signal, move to a location with a stronger signal.


Handle your Apple Watch and its accessories safely

Apple Watch, its power adaptor and Apple Watch Magnetic Charging Cable follow applicable surface-temperature standards and limits. Even within these limits, sustained contact with warm surfaces for long periods of time may cause discomfort or injury.

Here are some safety tips:

  • Be aware that Apple Watch, its power adaptor and Apple Watch Magnetic Charging Cable will warm up when plugged into a power source.
  • If plugged in, Apple Watch, Apple Watch Magnetic Charging Cables and power adaptors shouldn't be in prolonged contact with skin.
  • While charging, Apple Watch, its power adaptor and Apple Watch Magnetic Charging Cable should stay in a well-ventilated area. For example, if these devices are charging or plugged into power sources, they shouldn't be covered.
  • Use of mobile data on Apple Watch cellular models may make the device feel warm. 
  • Take off your Apple Watch if it becomes uncomfortably warm. Take special care if you have a physical condition that affects your ability to sense heat against the body.

Apple Watch, its adaptor and Apple Watch Magnetic Charging Cable meet the standard for Safety of Information Technology Equipment, IEC 60950-1:2005+A1:2009+A2:2013. Many countries and regions have adopted this safety standard. For example, it’s referred to as:

  • UL 60950-1 in the United States
  • CSA 60950-01 in Canada
  • EN 60950- in Europe
  • AS/NZS 60950:1 in Australia and New Zealand
Published Date: