The authors agree that this surname originates in the adjective invernicio / invernizio, referring to that which appears or is born in winter, and that its presence is characteristic of the region of Lombardy, with a particular hold in the Lecco area and the Valsassina.

E. Rossoni notes that the earliest documented form appears in the Codex Diplomaticus Mediolanensis: in 1174 a certain Invernus Dalapiscina is cited in Milan. He further proposes that the adjective invernizzo —today replaced by invernengo— was used in the dialects of Lombardy to indicate that which occurs or is born in winter, such as wheat sown in late autumn, and that the name Iverno or Inverno (from the Latin Hibernus) would have designated people born in that season. Rossoni likewise mentions a parchment of 1391 preserved in the Biblioteca Civica A. Mai of Bergamo, in which Zano Invernizis, a native of Lecco, is named.

Rossoni adds two further hypotheses: a connection with the locality of Erna, at the foot of the Resegone, whose name would derive from the Latin vernus ("of spring"); and another going back to the Valtellina dialect adjective invernìsc, "angry" or "sullen", with a metaphorical transfer of the characteristics of the winter climate to traits of character, so that the surname may have functioned as a nickname for surly or unsociable people.

A possible connection with the place name Inverno e Monteleone, a locality in the Pavia area, is also considered. The historical presence of the surname in the Valsassina is attested from the 16th and 17th centuries in localities such as Acquate, Ballabio, Laorca, Morterone, Cremeno, Maggio, Mezzaca and Colmine.