What is a "Split Night"?
A split night is when a baby or toddler wakes up in the middle of the night and stays awake for an extended period-typically 1 to 3 hours-while being alert, playful, and often happy. This is different from typical night wakings, where a child briefly wakes and can be soothed back to sleep. During a split night, usual settling methods often don’t work, and the child remains awake until they naturally tire out and fall back asleep.
Split nights are most common between 8 and 24 months of age but can occur at other ages too. They are usually not caused by hunger, discomfort, or a need for comfort, but rather by a mismatch between the child’s sleep pressure (the drive to sleep that builds during wakefulness) and their circadian rhythm (internal body clock). Common causes include too much daytime sleep, an early bedtime, or developmental milestones that disrupt sleep patterns.
While split nights can be exhausting for parents, they are considered a normal and healthy sleep pattern for some children and are often temporary.
So WHY do they happen?
It’s All About Sleep Pressure + Circadian Rhythm
Split nights are most often caused by a mismatch between your child’s sleep pressure (their body’s natural drive to sleep) and their circadian rhythm (internal body clock).
When a baby naps too long in the day or goes to bed before they’re truly tired, they might not build up enough sleep pressure to stay asleep all night. Instead, they wake in the early hours feeling refreshed, alert and—much to your horror—ready to play.
Too Much Daytime Sleep
An extra-long nap (especially late in the day) can “steal” sleep from the night. This leads to those long, wide-awake stretches where your baby isn’t fussy—they’re just not tired.
An Early Bedtime
While early bedtimes are often recommended, if your child is consistently waking for long periods overnight, a slightly later bedtime might help build more sleep pressure and reduce split nights.
Developmental Milestones
Big leaps like crawling, walking, or language bursts can also disrupt overnight sleep. Their little brains are working overtime—even at night—which can trigger longer wakeful periods.
While split nights can be draining, they’re usually a temporary phase. With a few gentle tweaks to your child’s sleep routine, you can often ease the impact and help their body clock settle back into sync.
Feeling exhausted and unsure how to handle split nights?
You’re not doing anything wrong—and you don’t have to figure it out alone. As a midwife and IBCLC, I offer virtual consultations to help you navigate sleep challenges with gentle, evidence-based support that suits your family.
Book a virtual consultation today and let’s work through it together, one sleep-deprived night at a time.
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