How to Hatch Chicken Eggs: Incubator Temperature and Humidity Chart

The numbers at a glance

	Days 1–18	Days 19–21 (lockdown)
Temperature, fan (forced-air) incubator	about 99.5–100°F	same
Temperature, still-air incubator	about 100.5–102°F	same
Humidity	58–60% RH	65% RH or more
Turning	at least 4–6 times a day (or automatic)	stop turning

Ranges from Mississippi State, Utah State and University of Illinois Extension. Sources differ slightly; always follow your incubator's manual, and check it with a separate thermometer and hygrometer.

Before you set eggs

Run the incubator empty for 24 hours and confirm it holds temperature and humidity.
Use clean, fertile eggs. Mississippi State recommends setting eggs within 7 days of lay, stored at about 55°F and 75% humidity with the small end pointing down. Do not wash them.
Let eggs warm to room temperature for a few hours before setting so condensation does not form.

Day by day

Day	What to do
Day 1	Set eggs, pointed end slightly down. Start turning (or switch on the automatic turner).
Days 1–7	Hold temperature and humidity steady. Open the incubator as little as possible.
Days 7–10	First candling: remove clear (infertile) eggs.
Days 10–17	Keep turning; top up water as needed. Optional second candling around day 14.
Day 18	Lockdown: stop turning, remove the turner if your model needs it, raise humidity to 65% or more, close the lid.
Days 19–21	Do not open the incubator. Chicks pip, then zip, usually on day 21.
After hatch	Leave chicks in the incubator until dry and fluffy (up to 24 hours), then move them to a warm brooder.

Candling

Shine a bright light through the egg in a dark room. Around day 7 a fertile egg shows a web of blood vessels and a dark spot; a clear egg is infertile. A ring of blood with no vessels means the embryo died early. Remove both, since they can spoil. Incubators like the Nurture Right 360 and MATICOOPX have built-in candling lights.

Lockdown and hatch

Every source agrees on the key rule: stop turning for the last three days and keep the lid shut. Opening it drops humidity just as chicks are breaking through, which can leave them stuck to the membrane. Resist helping chicks out; most need many hours between first pip and hatch.

After hatch: the brooder

Week	Temperature at chick level
1	90–95°F
2	85–90°F
3	80–85°F
4	75–80°F
5+	keep dropping about 5°F a week until 65–70°F

From Penn State, Oklahoma State and Missouri Extension: start at 90–95°F and lower about 5°F per week.

Feed chick starter (18–20% protein) and fresh water in a shallow chick fount. Watch the chicks: huddled under the heat means too cold, spread to the edges and panting means too hot.

How to Hatch Chicken Eggs in an Incubator