Switch your Mac between Celsius and Fahrenheit, or metric and imperial

Why it happens

Your Mac picks units from the region chosen when it was set up, so a Mac bought or set up abroad can show units you don't use. Two settings in Language & Region control them for the whole Mac. Many apps follow them, unless they have a units setting of their own.

How to fix it

1. Click the Apple menu, choose System Settings, click General in the sidebar, then Language & Region.

2. Open the Temperature menu and choose Celsius or Fahrenheit.

   General›Language & Region›Temperature

3. On the same page, open Measurement system and choose Metric for kilometres and kilograms, US for miles and pounds, or UK for the British mix.

4. Quit and reopen any app that's open, such as Weather, so it picks up the new units.

Still not fixed?

1. If only the Weather app still shows the old units, it has its own Units settings. In Weather's settings, set Temperature to Use system setting, or click Restore Defaults, so it follows your Mac.

2. If you change Region later, check Temperature and Measurement system again. Picking a new region can switch them to that region's usual units.

   General›Language & Region›Region

3. Some apps from other makers keep their own unit settings. Look in that app's Settings, usually in its menu next to the Apple menu.

4. If the settings won't change or keep switching back after a restart, contact Apple Support.