# Rainfall frequency

From AMS Glossary

## rainfall frequency

- (
*Also called*frequency curve.) The probability distribution specifying the exceedance probability of different rainfall depths for a given duration (such as 1 hour,*or*a 24-hour day).

The exceedance frequency is often reported as a return period (in years), which is the reciprocal of the annual exceedance frequency.

- The expected number of times, during a specified time period, that a given precipitation depth will be exceeded.