The sleep of an 8-month-old baby

Eight months is the month when a baby who was sleeping very well starts waking again, and parents wonder what they missed.

They missed nothing. Around eight months, your baby grasps something new and fundamental: you carry on existing when they cannot see you. It is a major cognitive step forward — and very bad news for their nights, because they now know you are somewhere, and that they can call you.

It passes. Count in weeks rather than days, and know that it is not a loss of skill: sleep goes back to where it was.

Sleep per 24 h

12 – 15 h

Of which at night

10 – 12 h

Naps

2 – 3

Awake window

2 h 30 – 3 h

One cycle lasts

~ 60 min

Before putting down

~ 15 min

The key point at this age

What helps, and what makes it worse

What helps: playing peekaboo during the day, leaving the room while saying you are coming back and actually coming back, keeping the bedtime routine identical and predictable. What makes it worse: slipping away while they are looking elsewhere. It avoids one cry in the moment, and it teaches them that people can disappear without warning — so it is better to stay alert.

Your baby’s age

Birth1 year2 years3 years

They fell asleep at

You’re looking at

They fall asleep

Their night at 8 months, minute by minute

The whole night, at a glance

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The timer: when can I put them down?

Start it the second they fall asleep in your arms.

Your baby’s age

While you wait, keep them against you and try not to move. The countdown will tell you when their sleep is deep enough for the transfer.

Keep this tab open. The timer stays accurate even if the screen turns off.

Two naps, and the wakings return

The rhythm simplifies — two well-established naps — but separation anxiety arrives, and with it a wave of night wakings that has nothing to do with sleep.

The move from three naps to two usually happens between six and nine months, and in fits and starts.
Around eight months they understand you exist even when they cannot see you: a real step forward — and one that wakes them.
Sitting or standing up in the cot at night is common: they are practising, even half-asleep.
Teething disrupts things, but rarely for more than a few nights in a row.

The classic trap

A baby who slept well and starts waking again at eight months has not "lost" what they learned. They are going through a developmental stage, and it settles.

Falling asleep alone at this age

✓ Possible

Falling asleep alone is established for many, but separation anxiety can set it back for a few weeks. That is not a loss of skill, it is a parenthesis.

Put down awake, a child of this age usually takes 10 to 20 minutes to fall asleep. That squirming is normal.

How much sleep they need, age by age

The shaded band is the normal range over 24 hours. Hover to read an age range.

Total sleep over 24 hOf which at night

Hover over the curve to read an age range.

The questions of this age

How long does separation anxiety last at night?

The peak usually lasts a few weeks, with occasional returns until around eighteen months, often after a change — going back to work, starting nursery, moving house.

My eight-month-old cries the moment I leave the room — what do I do?

Reassure them without taking them out of the cot, with a brief and predictable presence: calm voice, hand on them, then leave. You can shorten it gradually. What matters is that it is always the same: predictability reassures, not the length of the visit.

Can teeth explain waking at 8 months?

They contribute, but rarely for more than a few nights around the eruption. If the wakings last several weeks, the cause is almost always elsewhere — and at eight months, separation anxiety is the first suspect.

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