The SCS 24-hr. rainfall distributions are classic examples of dimensionless depth rainfall distributions. The Y-axis is dimensionless so that different rainfall depths can be applied to the distributions to create rainfall curves for various storm magnitudes and geographic locations.

The following figure displays four SCS distributions used in the United States (Types I, IA, II, and III).

24-Hour Rainfall Distributions

The approximate geographic boundaries for these rainfall distributions are shown below.

Approximate Boundaries