This small command modification allows you to detect biomes in Minecraft 1.13


/scoreboard objectives setdisplay sidebar playerBiome

 ▶ [Create world and scoreboard] The first thing you have to do is to create a world, and once in, type in chat the two commands you see at the top of this page.

 ▶ [Download and import datapack] Download my biome detection datapack by clicking here, import the downloaded archive file in the "datapacks" folder of your world and extract it. After you extracted it, make sure to delete the archive file.

 ▶ [Join world!] Join your world and you should see your scoreboard objective score update when you change biomes. If you had your world already open, make sure to type in chat /reload​​

/scoreboard objectives add playerBiome dummy