Adult green frogs attain a snout-vent length (excluding the hind legs) of 5.5 to 9 cm (2.25 to 3.5 in).

Where the green back and sides fade into the white belly and chest, some black mottling may occur.

The most prominent feature is the pair of dorsolateral folds extending from behind the tympanic membranes to just beyond halfway down the back.

The northern green frog dwells in marshes, swamps, ponds, lakes, springs, and other aquatic environments.

Crickets, night crawlers and meal worms provide adequate nutrition.