Tuna
Fish
Doneness
Rare
43–46 °C109–115 °F
Cool red center, very soft.
Medium rare
49–52 °C120–126 °F
Warm red center, springy. The classic steak doneness.
Medium
54–57 °C129–135 °F
Warm pink center, firm.
Well done
63–65 °C145–149 °F
No pink, fully cooked through.
Tip
Sear or serve raw only if labeled sushi-grade. Tuna steak is typically served rare to medium rare in the center.
USDA guidance
USDA recommends a minimum internal temperature of 63 °C / 145 °F
Source