Split Nights: Why Your 9-12 Month Old is Waking for Hours
Does your 9-12 month old wake up for hours in the middle of the night, acting like it’s daytime? This frustrating sleep issue, known as split nights, can leave you feeling exhausted and confused. Instead of quickly settling back to sleep, your baby seems wide awake, happy, and ready to play. It can be a confusing, exhausting battle, you may be wondering…..what should you do?
Here is some good news! By making a few simple adjustments, you can help your baby sleep through the night again!
What Are Split Nights?
A split night happens when a baby wakes up and stays awake for an extended period, usually 1-3 hours in the middle of the night. Unlike typical night wakings, babies with split nights often seem alert, happy, and ready to play.
Key sign of a split night: If your baby wakes up but isn’t crying or upset, it’s likely due to a sleep schedule imbalance rather than a need for a feeding.
Why Do Split Nights Happen in Babies?
Most split nights occur because of an imbalance in daytime sleep and wake windows, leading to disrupted sleep cycles.
1. Not Enough Sleep Pressure Before Bedtime
Babies need enough time awake before bed to build up sleep pressure, being tired enough to fall asleep easily. If the last wake window is too short, your baby may wake up in the middle of the night feeling ready for the day.
2. Too Much Daytime Sleep
If your baby naps too much during the day, they may not be tired enough for a full night’s sleep. At 9-12 months, most babies need 2.5–3 hours of total daytime sleep split into two naps.
3. The 9-12 Month Sleep Regression
Many babies experience a sleep regression between 9-12 months, due to big developmental milestones like crawling, standing, and babbling. Their brains are busy processing these new skills, which can lead to middle-of-the-night wake-ups.
4. Overstimulation Before Bedtime
If bedtime includes bright lights or screen time, melatonin production may be disrupted, making it harder for your baby to sleep through the night.
How to Fix Split Nights in Babies (9-12 Months)
If your baby is waking up for long stretches at night, try these expert sleep training tips to help them sleep through the night.
1. Adjust Wake Windows for 9-12 Month Olds
At this age, wake windows need to be long enough to build enough sleep pressure but not so long that your baby becomes overtired.
| Age | 1st Wake Window | 2nd Wake Window | 3rd Wake Window (Before Bed) |
|---|---|---|---|
| 9-10 months | 2.5-3 hours | 3 hours | 3-3.5 hours |
| 11-12 months | 3 hours | 3-3.5 hours | 3.5-4 hours |
Tip: The wake window before bedtime is the most important! If it’s too short, your baby may wake up in the middle of the night.
2. Follow a Consistent 9-12 Month Sleep Schedule
A predictable sleep schedule can help regulate your baby’s sleep cycles and prevent night wakings.
Example Sleep Schedule for a 10-Month-Old:
- 7:00 AM – Wake up
- 10 AM – 11:30 AM – Nap 1
- 2:30 PM – 4 PM – Nap 2
- 7:30 PM – Bedtime
3. Keep Night Wakings Low-Stimulation
If your baby wakes up in the middle of the night, avoid accidentally reinforcing split nights by making wake-ups fun or engaging. Instead:
✔ Keep the room dark
✔ Use a calm, quiet voice
✔ Offer minimal interaction (no playtime!)
✔ Avoid unnecessary night feeds (if baby is developmentally ready)
4. Encourage Independent Sleep Skills
If your baby relies on rocking, nursing, or being held to fall asleep, they may struggle to resettle on their own during the night.
Try this: Put your baby down awake at bedtime so they learn to fall asleep independently.
If needed, a gentle sleep training method can help teach self-settling skills while keeping nighttime wake-ups brief.
When Will Split Nights Stop?
If you adjust wake windows and naps correctly, you should see improvement within 3-5 nights. Some babies need a little more time, so stay patient and consistent! Reach out to me for support and book an appointment if you’d like some help with your baby’s schedule.
Final Thoughts: You Can Fix Split Nights!
Split nights can be exhausting, but small sleep schedule adjustments can make a huge difference. Trust your instincts, stay consistent, and give your baby time to adjust.
Need expert help with your baby’s sleep? Book a one-on-one sleep consultation, and let’s get your little one (and you!) the rest you need.