Where is basal body temperature typically measured for accuracy?

Basal body temperature is best measured rectally for accuracy. This method gives a reliable indicator of core body temperature, which can reflect subtle changes that occur during the menstrual cycle, particularly when tracking ovulation. The rectal temperature is typically higher than oral or axillary (armpit) temperatures and remains stable, making it a preferred method for those monitoring for fertility or hormonal changes.

Measuring basal body temperature in the mouth is less reliable due to variations caused by factors such as recent eating, drinking, or breathing patterns, which can affect the readings. Similarly, measuring under the armpit can yield even less accurate results, as this site may not reflect internal changes as directly. Although vaginal measurement is somewhat more accurate than oral or axillary methods, it does not provide the same level of precision as rectal measurement, making it less preferable for tracking basal body temperature specifically. Thus, rectal measurement is recognized as the gold standard for accurately determining basal body temperature.