What is a normal temperature?
A normal temperature is about 98.6F when taken orally (by mouth). Temperatures taken rectally (by rectum) usually run 1 higher than those taken orally. So a normal temperature is about 99.6F when taken rectally. Many doctors define a fever as an oral temperature above 99.4F or a rectal temperature above 100.4F.
A normal of temperature, precipitation or any other weather element is the average of the observed values of that element over a period of time. The period of time depends on how long the particular weather station has been in service. The word “normal” can be misleading because values other than the “normal” are not unusual. By international agreement, averages or normals cover a 30-year period from the beginning of one decade to the end of the third, e.g., from 1971 to 2000. For example, to calculate the normal daytime high temperature for Winnipeg on September 15, add together the daily high temperatures on this day for the 30 years from 1971 to 2000 and divide the total by 30. This quotient is the average or normal daytime high temperature for September 15 from 1971 to 2000 inclusive. Normals give a general idea of what conditions might be expected on that date.
