1. A method comprising: determining, by a system having a processor, an adaptive baseline that includes at least one statistical parameter based on values of a metric that are provided at irregular intervals; wherein the determining includes: computing the statistical parameter using a forgetting factor that causes different weights to be placed on the corresponding values of the metric; and calculating the forgetting factor based on a difference between the irregular intervals, wherein the irregular intervals comprise first successive intervals that are separated by a first gap, and second successive time intervals that are separated by a second gap different from the first gap, and wherein a value of the calculated forgetting factor for the first successive intervals is different from a value of the calculated forgetting factor for the second successive intervals; and detecting, by the system using the adaptive baseline, an abnormal behavior of a monitored environment indicated by a given value of the metric.