Specific heat capacity (c) measures how much energy a substance can absorb per unit mass per degree temperature change. Units: J/(kg·K) or cal/(g·°C).
Formula
Q = mcΔT, where Q = heat energy (J), m = mass (kg), c = specific heat, ΔT = temperature change (K or °C).
Common Values (J/kg·K)
- Water: 4,186 — highest of common materials
- Aluminum: 897
- Iron: 449
- Copper: 385
- Air: 1,005
Water's high specific heat is why coastal climates are milder than inland — oceans absorb/release heat slowly.
Why Coastal Climates Are Milder
Water's unusually high specific heat capacity means large bodies of water absorb enormous amounts of heat in summer and release it slowly in winter, moderating nearby air temperature. This is the physical reason coastal cities typically see smaller seasonal temperature swings than inland cities at the same latitude.
Specific Heat in Cooking
Cast iron has a relatively low specific heat compared to water, meaning it heats up quickly — but its high mass means it also stores a lot of total heat energy once hot, which is why cast iron pans stay hot long after being removed from a burner, ideal for searing.