A temperature rhythm acquisition apparatus comprising: a data acquirer configured to acquire wrist temperature data of a user and external environment temperature data; and a processor configured to estimate wrist temperature rhythm data in which an influence of an external environment temperature is corrected, based on determining whether a determined amount of change in the acquired wrist temperature per unit time and a determined amount of change in the acquired external environment temperature per unit time satisfy a first condition or a second condition, removing first wrist temperature data in a predetermined time range, from the acquired wrist temperature data, based on a reference time point for determining the amount of change in the wrist temperature per unit time, to generate remaining wrist temperature data, in response to the determined amount of change in the wrist temperature per unit time and the determined amount of change in the external environment temperature per unit time satisfying the first condition or the second condition, and interpolating the removed first wrist temperature data based on the remaining wrist temperature data, wherein the first condition is that the amount of change in the wrist temperature per unit time is less than a first threshold and the amount of change in the external environment temperature per unit time that corresponds to the amount of change in the wrist temperature per unit time is less than a second threshold, or that the amount of change in the wrist temperature per unit time is greater than a third threshold and the amount of change in the external environment temperature per unit time that corresponds to the amount of change in the wrist temperature per unit time is greater than a fourth threshold, and wherein the second condition is that an absolute value of the amount of change in the external environment temperature per unit time is greater than a fifth threshold. a data acquirer configured to acquire wrist temperature data of a user and external environment temperature data; and a processor configured to estimate wrist temperature rhythm data in which an influence of an external environment temperature is corrected, based on determining whether a determined amount of change in the acquired wrist temperature per unit time and a determined amount of change in the acquired external environment temperature per unit time satisfy a first condition or a second condition, removing first wrist temperature data in a predetermined time range, from the acquired wrist temperature data, based on a reference time point for determining the amount of change in the wrist temperature per unit time, to generate remaining wrist temperature data, in response to the determined amount of change in the wrist temperature per unit time and the determined amount of change in the external environment temperature per unit time satisfying the first condition or the second condition, and interpolating the removed first wrist temperature data based on the remaining wrist temperature data, wherein the first condition is that the amount of change in the wrist temperature per unit time is less than a first threshold and the amount of change in the external environment temperature per unit time that corresponds to the amount of change in the wrist temperature per unit time is less than a second threshold, or that the amount of change in the wrist temperature per unit time is greater than a third threshold and the amount of change in the external environment temperature per unit time that corresponds to the amount of change in the wrist temperature per unit time is greater than a fourth threshold, and wherein the second condition is that an absolute value of the amount of change in the external environment temperature per unit time is greater than a fifth threshold. <EOS>