Nesting is done, by the females only, between late May and mid-July.
The nests are vase-shaped and are usually dug in sandy soil, often at sites with southern exposures.
Nests are often within 200 m (220 yd) of water, but may be as far away as 600 m (660 yd), with older females tending to nest further inland.
Nest sizes vary depending on female sizes and locations but are about 5–11 cm (2–4 in) deep.
Females may return to the same sites several consecutive years, but if several females make their nests close together, the eggs become more vulnerable to predators.

The female's optimal body temperature while digging her nest is 29–30 °C (84–86 °F).
If the weather is unsuitable, for instance a too hot night in the Southeast, she delays the process until later at night.
Painted turtles in Virginia have been observed waiting three weeks to nest because of a hot drought.

While preparing to dig her nest, the female sometimes exhibits a mysterious preliminary behavior.
She presses her throat against the ground of different potential sites, perhaps sensing moisture, warmth, texture, or smell, although her exact motivation is unknown.
She may further temporize by excavating several false nests as the wood turtles also do.

The female relies on her hind feet for digging.
She may accumulate so much sand and mud on her feet that her mobility is reduced, making her vulnerable to predators.
To lighten her labors, she lubricates the area with her bladder water.
Once the nest is complete, the female deposits into the hole.
The freshly laid eggs are white, elliptical, porous, and flexible.
From start to finish, the female's work may take four hours.
Sometimes she remains on land overnight afterwards, before returning to her home water.

Females can lay five clutches per year, but two is a normal average after including the 30–50% of a population's females that do not produce any clutches in a given year.
In some northern populations, no females lay more than one clutch per year.
Bigger females tend to lay bigger eggs and more eggs per clutch.
Clutch sizes of the subspecies vary, although the differences may reflect different environments, rather than different genetics.
The two more northerly subspecies, western and midland, are larger and have more eggs per clutch—11.9 and 7.6, respectively—than the two more southerly subspecies, southern (4.2) and eastern (4.9).
Within subspecies, also, the more northerly females lay larger clutches.
Nesting is done, by the females only, between late May and mid-July. The nests are vase-shaped and are usually dug in sandy soil, often at sites with southern exposures. Nests are often within 200 m (220 yd) of water, but may be as far away as 600 m (660 yd), with older females tending to nest further inland. Nest sizes vary depending on female sizes and locations but are about 5–11 cm (2–4 in) deep. Females may return to the same sites several consecutive years, but if several females make their nests close together, the eggs become more vulnerable to predators.
The female's optimal body temperature while digging her nest is 29–30 °C (84–86 °F). If the weather is unsuitable, for instance a too hot night in the Southeast, she delays the process until later at night. Painted turtles in Virginia have been observed waiting three weeks to nest because of a hot drought.
While preparing to dig her nest, the female sometimes exhibits a mysterious preliminary behavior. She presses her throat against the ground of different potential sites, perhaps sensing moisture, warmth, texture, or smell, although her exact motivation is unknown. She may further temporize by excavating several false nests as the wood turtles also do.
The female relies on her hind feet for digging. She may accumulate so much sand and mud on her feet that her mobility is reduced, making her vulnerable to predators. To lighten her labors, she lubricates the area with her bladder water. Once the nest is complete, the female deposits into the hole. The freshly laid eggs are white, elliptical, porous, and flexible. From start to finish, the female's work may take four hours. Sometimes she remains on land overnight afterwards, before returning to her home water.
Females can lay five clutches per year, but two is a normal average after including the 30–50% of a population's females that do not produce any clutches in a given year. In some northern populations, no females lay more than one clutch per year. Bigger females tend to lay bigger eggs and more eggs per clutch. Clutch sizes of the subspecies vary, although the differences may reflect different environments, rather than different genetics. The two more northerly subspecies, western and midland, are larger and have more eggs per clutch—11.9 and 7.6, respectively—than the two more southerly subspecies, southern (4.2) and eastern (4.9). Within subspecies, also, the more northerly females lay larger clutches.
Painted turtle