Your Hyundai Accent can show outdoor temperature in Celsius or Fahrenheit, this guide shows you how to switch between the two.

Tip: You can cycle through the display screens using the Trip button to range Trip A or Trip B screen.
Changing temperature unit
If you’d like to change the unit from Fahrenheit to Celsius, hold down the Trip button for five seconds.
My Hyundai Accent hatchback temperature got switched from Fahrenheit to Celsius sometime this summer and I haven’t been able to switch it back either by reading the manual or watching your video (pressing and holding the “Trip” button for 5 seconds, I’ve tried it for 5 seconds and just holding it until it switches, nearly a minute, and it doesn’t work either way). Do you have any other suggestions? It’s not a major issue so I’m fine if it won’t go back, it’s just nice to know the outside temp without having to do the conversion every time.
Nevermind, I found another video that showed them pressing the button and I noticed it was on range, I had it on average mpg and for some reason that did the trick.
Thank you! I have been trying to change it with no luck. You solved it for me!