The normal body temperature for an adult typically ranges between about 97°F (36.1°C) and 99°F (37.2°C), with the average often cited as 98.6°F (37°C). However, this "normal" range can vary depending on the individual, time of day, age, activity level, and measurement method. For example, oral temperatures usually range from 96°F to 98°F (35.6°C to 36.7°C), while rectal temperatures tend to be slightly higher, around 97°F to 99°F (36.1°C to 37.2°C)
. Body temperature is generally lowest in the early morning and can rise throughout the day. Older adults tend to have slightly lower normal body temperatures compared to younger adults
. Temperatures above 100.4°F (38°C) are usually considered a fever, indicating infection or illness
. In summary:
- Typical adult normal temperature range: 97°F to 99°F (36.1°C to 37.2°C)
- Average commonly cited: 98.6°F (37°C)
- Varies by individual, age, time of day, and measurement site
- Fever threshold: above 100.4°F (38°C)
This variation means it is useful to know your own baseline temperature when healthy, rather than relying on a single fixed number
