Extremes seldom last long.

Conditions at either extreme—whether unusually favorable or unusually harsh—are often temporary. The saying counsels against assuming that an intense situation will continue unchanged.

It can encourage patience during hardship and restraint during prosperity. It expresses a general tendency, not a dependable prediction: some extreme conditions can persist, even though exceptional intensity is often less stable than ordinary conditions.

Use it as a measured comment on a spell of severe difficulty, intense emotion, exceptional weather, or unusual success. It suits situations where someone needs perspective about a condition that feels overwhelming or unusually fortunate, without promising that it will end soon.