Cumulative Distribution Function

The cumulative distribution function F(x) of a variable gives the probability that the variable will take on a value less than or equal to a number x.

The example below shows that the temperature is below 40°C all the time, below 20°C about 72% of the time, below 10°C about 41% of the time, below 0°C about 16% of the time, and below -10°C about 3% of the time:

Within Windographer, we often abbreviate cumulative distribution function as CDF.