125°F is the sweet spot for tuna.

125°F (about 52°C). That’s medium-rare in tuna. Any higher and you’re basically eating canned fish with grill marks.

Tuna is lean and dries out fast. At 125°F the center stays translucent, tender, and almost buttery. If you pull it at 130°F, carryover cooking will push it past medium. At 130°F it’s still okay but starting to flake. At 135°F? You’ve ruined it.

Use a good instant-read thermometer. Pull it off the heat when it hits 120-122°F and let it rest for a few minutes — it’ll coast up to 125°F. If you don’t have a thermometer, sear the outside hard, 90 seconds per side on a one-inch steak, and call it close enough.

Don’t overcook tuna. It’s not a burger.