<p>If a rate of metal oxidation is diffusion-controlled, then a thickness of a scale emerging on its surface at constant temperature is typically a parabolic function of time. If temperature changes, then this inherently parabolic temporal evolution of the thickness may transform into differently shaped functions. By using a concept of equivalent times introduced and elaborated in this work, it is shown how the oxide thickness versus time dependence <i>L</i>(<i>t</i>) can be established for any time–temperature profile <i>T</i>(<i>t</i>). Then, it is explored whether there exists a unique <i>T</i>(<i>t</i>) regime for which a growth rate is constant, i.e., for which <i>L</i>(<i>t</i>) is linear. It is proven that it is possible to design a time–temperature scheme for which the same holding times cause identical thickness changes. Such a growth mode, however, cannot be sustained indefinitely; there is a time threshold beyond which the linear growth of the oxide layer cannot be maintained any longer. Although oxidation is frequently a thermally activated process, mathematical expressions and conclusions remain the same for non-Arrhenius kinetics.</p>