Dolbear's law states the relationship between the air temperature and the rate at which crickets chirp. It was formulated by physicist Amos Dolbear and published in 1897 in an article called "The Cricket as a Thermometer". Dolbear's observations on the relation between chirp rate and temperature were preceded by an 1881 report by Margarette W. Brooks, although this paper went unnoticed until after Dolbear's publication.

Crickets are orthopteran insects which are related to bush crickets, and, more distantly, to grasshoppers. In older literature, such as Imms, "crickets" were placed at the family level, but contemporary authorities including Otte now place them in the superfamily Grylloidea. The word has been used in combination to describe more distantly related taxa in the suborder Ensifera, such as king crickets and mole crickets.