Cast Iron's Extreme Heat
A well-seasoned cast iron skillet can reach 700°F on a home burner — hotter than most ovens go.
The Science Summary
Cast iron's high thermal mass means it stores enormous amounts of heat and releases it evenly. On a powerful home burner, a dry cast-iron skillet can reach 500–700°F (260–371°C) — far beyond what most ovens achieve.
Thermal Mass vs. Conductivity
Cast iron is actually a relatively poor conductor of heat compared to aluminum or copper, meaning it heats up unevenly. However, it excels in a different metric: thermal mass. Thermal mass refers to a material's ability to absorb and store heat.
Because cast iron pans are heavily constructed, they hold an immense amount of thermal energy. When you place a cold, thick steak into an aluminum pan, the pan's temperature rapidly drops, causing the meat to steam in its own juices. When you drop that same steak into a preheated cast iron pan, the pan doesn't flinch—it aggressively continues transferring stored heat into the meat, yielding a stunning, rapid sear.
Managing the Heat
A home stove burner on high can easily push a dry cast iron skillet past 600°F or 700°F (315°C to 371°C). At these extreme temperatures, virtually any cooking oil will instantly exceed its smoke point and begin to polymerize into a sticky residue or burn completely, creating acrid flavors.
To sear effectively at high heat, chefs recommend using oils with high smoke points like avocado or refined safflower oil, and maintaining the pan closer to 450°F–500°F (230°C–260°C). Always preheat cast iron slowly over medium heat for 5-10 minutes to resolve its poor conductivity and ensure an even cooking surface before blasting it to maximum temperature.
Related Temperatures — click to copy
Sources & Further Reading