Baby Sleep at 6 to 9 Months: What Changes, What Is Normal, and What Helps

The period from 6 to 9 months is one of the most dynamic in your baby's first year, and every one of these developmental leaps can affect sleep. Understanding what is happening in your baby's brain and body helps explain why sleep can feel like it has taken a step backwards — even if it was going well before.

Physically: Your baby is likely sitting independently (most babies master this between 6 and 8 months), rolling confidently in both directions, and may be starting to crawl — some begin commando crawling from around 7 months. Some babies begin pulling to stand from around 8 to 9 months. Every new physical skill creates a compulsion to practise, including at 2am in the cot.

Cognitively: The biggest development in this window is object permanence — your baby is beginning to understand that people and things continue to exist when they cannot see them. This is a fundamental cognitive leap that directly affects sleep. Before object permanence, out of sight was literally out of mind. Now, when you leave the room, your baby knows you are somewhere else — and wants you back.

Emotionally: Separation anxiety typically emerges around 7 to 8 months, peaking between 8 and 10 months. Your baby may become clingy, cry when you leave the room, and protest being put down. This is not a behaviour problem — it is a sign that your baby has formed a deep, healthy attachment to you.

Feeding: Solids are being introduced from around 6 months per NHS guidance. This is a significant change in daily routine that can indirectly affect sleep — though the persistent myth that starting solids makes babies sleep through the night is exactly that: a myth. The NHS explicitly states that introducing solid food has no impact on helping babies sleep for longer.

Most babies in this age range need approximately 12 to 15 hours of total sleep in 24 hours (NHS guidance), with around 10 to 12 hours at night and 2 to 3.5 hours during the day across 2 to 3 naps.

Wake windows — the amount of time your baby can comfortably stay awake between sleeps — are gradually increasing:

• At 6 months: approximately 2 to 2.5 hours
• At 7 months: approximately 2.5 to 3 hours
• At 8 to 9 months: approximately 3 to 3.5 hours, with the longest window before bedtime

An important caveat: These are averages, not prescriptions. The Baby Sleep Information Source (BASIS, Durham University) emphasises that there is huge underlying variation in how much babies sleep. A baby sleeping 12 hours total may be perfectly healthy and well-rested. A baby sleeping 15 hours may also be perfectly healthy. Follow your baby's cues — mood, alertness, and how they respond to their schedule — rather than chasing specific numbers.

Wake windows are a useful guide, but they work best when combined with reading your baby's individual cues. Signs that your baby is ready for sleep include rubbing eyes, pulling ears, becoming quieter, losing interest in play, or becoming increasingly fussy. Watching for these cues alongside the clock gives you the best information about when your baby needs to sleep. For more on this, see our guide to overtired vs undertired signs.

The 8-month sleep regression — which can happen anywhere between 7 and 10 months — is driven by a perfect storm of developmental changes all arriving at once. It is one of the most challenging regressions for parents because so many things are changing simultaneously.

What is driving it:

• Object permanence: Your baby now knows you exist when you leave. This means they actively miss you and may protest being left alone to sleep
• Separation anxiety: Emotionally, your baby is processing the concept of your absence for the first time. This is not manipulation — it is a genuine developmental experience
• Motor milestones: Crawling, pulling to stand, and cruising create physical restlessness. Your baby may practise new skills in the cot instead of sleeping
• Language development: The brain is processing new sounds, words, and communication patterns, which can increase night-time brain activity
• Nap transition: Many babies are dropping from 3 naps to 2 during this period, which can temporarily create overtiredness

Unlike the 4-month regression (which reflects a permanent change in sleep architecture), the 8-month regression is temporary. It typically lasts 2 to 6 weeks, though it can feel much longer when you are in the middle of it.

The most important thing you can do during this period is maintain consistency. Keep your bedtime routine the same. Offer extra reassurance and comfort during the day. Avoid introducing new sleep habits (such as bringing baby into your bed for the first time or starting a new feeding pattern) that you will find difficult to sustain once the regression passes. Trust that if sleep was good before, it can return.

The 3-to-2 nap transition is one of the most significant schedule changes in the first year. It typically happens between 7 and 9 months, though some babies hold onto that third nap a little longer.

Signs your baby may be ready to drop the third nap:

• Consistently refusing or significantly shortening the third nap
• The third nap is pushing bedtime too late (past 7:30 to 8pm)
• Your baby is managing longer wake windows (3+ hours) without becoming overtired
• Night sleep is being disrupted by too much daytime sleep

A few important things to know about this transition:

• It rarely happens overnight. Expect 1 to 2 weeks of messy days where some days need 3 naps and some need 2. This is normal
• On 2-nap days, bring bedtime earlier. Even 6 to 6:30pm is appropriate during the transition to compensate for the lost nap. An earlier bedtime is nearly always the answer during nap transitions
• Extend wake windows gradually rather than suddenly dropping the nap one day and expecting your baby to handle much longer awake periods
• Flexibility is key. Follow your baby's cues. Some days they will need more sleep than others

The transition can feel chaotic while it is happening, but most babies settle into a reliable 2-nap schedule within a couple of weeks.

No. This is one of the most persistent myths in infant care, and the NHS explicitly states that introducing solid food has no impact on helping babies sleep for longer. Sleep is driven by brain maturation and sleep architecture, not stomach fullness.

That said, solids can indirectly affect sleep in other ways:

• Digestive discomfort if new foods are introduced too quickly or too close to bedtime
• Allergic reactions — which can cause discomfort and disturb sleep. Avoid introducing new allergens close to bedtime
• Constipation (common when starting solids, particularly with iron-fortified cereals) — which can cause discomfort at night
• Reduced milk intake if too many solids are given too soon — which can actually lead to more night waking from hunger

Breast milk or formula remains the primary source of nutrition until 12 months. Solids complement milk — they do not replace it at this stage. Offer solids during the day and ensure they are not displacing milk feeds.

Some babies do still need 1 to 2 night feeds at this age, and this is entirely normal. Breastfed babies in particular may still feed at night for both nutrition and comfort. If a baby who was previously sleeping longer stretches begins waking more for feeds, consider whether this is genuine hunger (active feeding, gulping, several minutes of swallowing) or a sleep association (brief comfort-suck and back to sleep).

Safe sleep guidance remains critically important at this age, even though the highest SIDS risk period (under 3 months) has passed. Nine out of ten SIDS cases occur before 6 months, but the risk does not become zero after this point.

Key Lullaby Trust guidance for 6 to 9 months:

• Back to sleep, every sleep. Even though your baby can now roll confidently, always place them on their back to start. Once they can roll both ways, they can be left to find their own sleeping position
• Clear cot. Firm, flat mattress with fitted sheet. No pillows, duvets, bumpers, wedges, or nests. A sleeping bag appropriate for the room temperature is the safest bedding option
• Room sharing. The Lullaby Trust recommends sharing a room for at least the first 6 months, for all sleeps. After 6 months, moving to their own room is a family choice
• Temperature. Room temperature of 16 to 20 degrees Celsius. Overheating is a known risk factor for SIDS
• Comforter introduction. A small, breathable comfort object (such as a muslin square) may be introduced from around 6 months. It should be small, lightweight, free from ribbons or detachable parts, and ideally removed once baby is asleep

If you are considering moving your baby to their own room after 6 months, think about timing. Moving during the peak of separation anxiety (typically 8 to 10 months) may make the transition harder. If possible, aim for around 6 to 7 months or wait until anxiety settles. Keep the sleep environment consistent — same sleeping bag, same white noise (if used), same bedtime routine.

It can be hard to know when sleep challenges are a normal part of development and when they warrant professional attention. Here is a general guide:

Normal at 6 to 9 months:

• Waking 1 to 3 times per night, including for feeds
• Some nights better than others — sleep is not linear
• Short naps (30 to 45 minutes), particularly the afternoon nap
• Resisting the third nap as the transition to 2 naps begins
• Crying at bedtime during separation anxiety peaks
• Practising sitting or crawling in the cot
• Taking 10 to 20 minutes to fall asleep

Worth speaking to your GP or health visitor about:

• Waking every 30 to 60 minutes all night, every night, for more than 2 to 3 weeks
• A sudden dramatic change in sleep with no obvious cause
• Baby seems excessively sleepy during the day (sleeping far more than 15 hours total)
• Inconsolable crying not related to tiredness, hunger, or a developmental phase
• Fever above 38 degrees Celsius, diarrhoea, or rash attributed to "teething" (the NHS states these are not teething symptoms)
• Persistent snoring, gasping, or pauses in breathing during sleep

Around a third of babies have never slept through the night by 12 months (BASIS, Durham University). Waking at night at this age is biologically normal and developmentally protective. It does not mean you are doing something wrong.

If you are ever concerned about your baby's health, speak to your GP or call NHS 111. This is sleep support, not medical advice.