Incubation lasts 72–80 days in the wild and for a similar period in artificial conditions.
In August and September, the young turtle breaks out from its egg, using a special projection of its jaw called the egg tooth.
Not all offspring leave the nest immediately, though.
Hatchlings north of a line from Nebraska to northern Illinois to New Jersey typically arrange themselves symmetrically in the nest and overwinter to emerge the following spring.

The hatchling's ability to survive winter in the nest has allowed the painted turtle to extend its range farther north than any other American turtle.
The painted turtle is genetically adapted to survive extended periods of subfreezing temperatures with blood that can remain supercooled and skin that resists penetration from ice crystals in the surrounding ground.
The hardest freezes nevertheless kill many hatchlings.

Immediately after hatching, turtles are dependent on egg yolk material for sustenance.
About a week to a week and a half after emerging from their eggs (or the following spring if emergence is delayed), hatchlings begin feeding to support growth.
The young turtles grow rapidly at first, sometimes doubling their size in the first year.
Growth slows sharply at sexual maturity and may stop completely.
Likely owing to differences of habitat and food by water body, growth rates often differ from population to population in the same area.
Among the subspecies, the western painted turtles are the quickest growers.

Females grow faster than males overall, and must be larger to mature sexually.
In most populations males reach sexual maturity at 2–4 years old, and females at 6–10.
Size and age at maturity increase with latitude; at the northern edge of their range, males reach sexual maturity at 7–9 years of age and females at 11–16.
Incubation lasts 72–80 days in the wild and for a similar period in artificial conditions. In August and September, the young turtle breaks out from its egg, using a special projection of its jaw called the egg tooth. Not all offspring leave the nest immediately, though. Hatchlings north of a line from Nebraska to northern Illinois to New Jersey typically arrange themselves symmetrically in the nest and overwinter to emerge the following spring.
The hatchling's ability to survive winter in the nest has allowed the painted turtle to extend its range farther north than any other American turtle. The painted turtle is genetically adapted to survive extended periods of subfreezing temperatures with blood that can remain supercooled and skin that resists penetration from ice crystals in the surrounding ground. The hardest freezes nevertheless kill many hatchlings.
Immediately after hatching, turtles are dependent on egg yolk material for sustenance. About a week to a week and a half after emerging from their eggs (or the following spring if emergence is delayed), hatchlings begin feeding to support growth. The young turtles grow rapidly at first, sometimes doubling their size in the first year. Growth slows sharply at sexual maturity and may stop completely. Likely owing to differences of habitat and food by water body, growth rates often differ from population to population in the same area. Among the subspecies, the western painted turtles are the quickest growers.
Females grow faster than males overall, and must be larger to mature sexually. In most populations males reach sexual maturity at 2–4 years old, and females at 6–10. Size and age at maturity increase with latitude; at the northern edge of their range, males reach sexual maturity at 7–9 years of age and females at 11–16.
Painted turtle