The normal human body temperature is commonly given as about 37 degrees Celsius.
That figure is a useful average, not a rigid target shared by every healthy person. Temperature changes with the time of day, age, activity, hormones, illness, and the location where it is measured. Core measurements are generally a little higher than oral measurements, while skin and underarm readings can be lower.
The 37 °C convention became influential through the work of German physician Carl Reinhold August Wunderlich. In the 19th century, his large collection of clinical temperature readings helped establish a standard reference for “normal” human temperature. Modern measurements suggest that the average is often closer to 36.8 °C, but 37 °C remains the canonical trivia answer.
A common mistake is treating 37 °C as the exact boundary between health and fever. Healthy temperatures naturally fluctuate, often being lower in the morning and higher later in the day. Measurement method matters too, so one reading should be interpreted in context rather than against a single universal number.