15 Month Sleep Regression: Here’s All You Need To Know!

Author Image By Paula McLaren - Norland Nurse NNEB RSH •  Updated: 08/09/23 •  Sleep / Sleep Regressions

toddler suddenly fighting sleep? Being fussy? Struggling to settle? The 15 month sleep regression has arrived. Here’s what that means, and what exhausted parents need to know to get through it.

What Is The 15 Month Sleep Regression?

How Long Does The 15 Month Sleep Regression Last?

The 15 month sleep regression, like all sleep regressions, commonly lasts between 2 and 6 weeks depending on the trigger. 

How Much Sleep Do 15 Month Olds Need?

Your 15 month old will need an average of 13-14 hours sleep in a 24 hour period with the bulk taken at night and the rest in 1-2 day time naps. 

However, not all 15-month-olds will need 2 naps per day and some may only take one long nap.

15 Month Sleep Regression Featured

15 Month Sleep Regression Signs

If your little one has been settling and sleeping well until now, the signs that your toddler is experiencing a sleep regression are:

Looking to get your little one to sleep quickly and effortlessly? Check out my Bedtime and Nap Cheat Sheet and master the art of making daytime naps and bedtimes as seamless as possible.

Causes Of The 15 Month Sleep Regression

As I mentioned earlier, sleep regressions can be caused by a variety of reasons, the main ones being environmental changes and developmental leaps…

However, there are other reasons why a 15 month sleep regression can occur and it’s important to know what they are to reduce the chances of a sleep regression from occurring and to navigate through one:

Causes Of The 15 Month Sleep Regression

1. They Are Reaching Big Physical, Mental And Emotional Developmental Milestones

A lot is going on physically at this age with your little one perfecting the art of walking, climbing and talking.

There is a lot going on cognitively as well as they become increasingly aware of the world around them and their place in it. All that extra brain and body activity can easily disrupt their sleep!

2. Their Sleep Needs Are Changing

Around this age, you may need to adjust daytime sleep, especially if newfound skills are making them more tired.

If they have started daycare they may need more sleep for a while as they adjust to the new routine too.

Some 15 month olds may also be going through a 2 to 1 nap transition, which if incorrectly managed, can trigger a sleep regression.

3. You Have Changed Their Environment And Routine

Moving house, going on holiday or visiting family overnight can all trigger a sleep regression.

And any major changes in routine could also upset an established sleep schedule such as starting daycare, parents returning to work or the primary caregiver changing.

4. Your Toddler Is Experiencing Separation Anxiety

Separation anxiety is also very common at this age and will make it difficult for your little one to fall asleep and to become distressed when they wake up at night and discover you’re not with them.

5. They’re Teething!

Your toddler’s first molars may start to erupt at this age.

If your little one is experiencing pain due to teething their sleep is very likely to be disrupted for a short while and although this is not a true sleep regression in itself, it may trigger one.

Investing in a natural teething toy can help soothe your toddler resulting in helping them sleep better!

Natural Untreated Wooden Teething Rings (12 Pieces)

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6. They Are Unwell

Like teething, illness may cause a sleep disruption for a short period of time and although this is not a true sleep regression, sickness can trigger a brief one as your little one may have been used to respond to every cry or unsettled sleep while they were unwell.

7. Hunger

With all the increased physical activity that your 15 month old is now capable of they may need more calories to keep them going.

It is very tempting to feed your toddler in order to get them back to sleep… however, this is not a habit you want to continue.

Offering mid-morning and mid-afternoon snacks can help as well as a milky drink before bed (a bottle or cup of formula or breastmilk depending on your preference and weaning stage).

Tips To Get Through The 15 Month Sleep Regression

If your little one does start to experience sleep troubles around 15 months of age, then there are some things you can do to help both you and your baby get through this sleep regression:

15 Month Sleep Regression Tips

1. Establish A Healthy Bedtime And Nap Routine 

Ensuring your little one gets consistent cues in preparation for sleep will go a long way in helping your little one fall asleep during a sleep regression. 

A regular bedtime and nap routine will do just that.

2. Stick To Your Routines 

I cannot stress how maintaining a healthy daily and bedtime routines will help to keep you sane and keep your little ones healthy development on track. 

I know life gets in the way sometimes, but being super vigilant about nap times, meal times and bedtimes, during a sleep regression will make your life so much easier during this time. 

So, if you have to cancel a few plans over the coming weeks to ensure you’re at home for naps and bedtime, it will be worth it in the long run.

3. Have Lots Of Cuddles

Sleep regressions can sometimes make your little one feel less secure. Offering extra cuddles and snuggle time can help reassure them as they navigate this tricky phase.

4. Keep Nighttime Interactions Low-Key

If your little one wakes at night then it’s super important to keep your interactions low-key. Have the lights down low and do not chat to 

them. A night light is a great investment as it stops you from having to turn on a light when visiting them at night.

My Top Pick
Toddler Night Light Lamp By LICKLIP

Finding the right night light for your child can be quite a task. You want something safe, comforting, and practical. The Cozy Starry Night Light ticks these boxes, with eye-friendly warm lighting and an easy-to-use dimmer.

Its gentle glow makes it the best night light for feeding baby, diaper changes, or comforting your little one back to sleep.

As your baby grows the Cozy Starry Night Light's starry sky projection can provide comfort and gentle quiet time stimulation. Its soft lighting ensures a dreamy, peaceful environment, supporting your baby’s natural sleep cycle.

It really is a fantastic nightlight (at a very reasonable price!)

  • Eye-friendly warm lighting with adjustable brightness.
  • Includes a timer function for convenience.
  • Projects a starry sky that is soothing for little ones.
  • Rechargeable battery, so it's very portable.
  • A USB adapter is not included for charging.
  • The star projector is static without motion (however, this is ideal for very young babies and toddlers).
  • Battery life varies based on the brightness settings.
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5. Teach Your Little One To Self-Settle

If you have not done so already, try and teach your little one to self-settle. Allow them to spend time playing in their cribs or a playpen while they are awake and put them down whilst drowsy and not fast asleep.

Read this post to learn more: How to Teach Baby To Self Soothe.

6. Try Not To Pick Them Up Every Time They Wake

It is very easy to fall into bad habits during a sleep regression so if your little one is waking more at night try leaving them to fuss for a short time when they wake, as they may just fall back to sleep without you having to go to them. 

If however, they start to become distressed, you should go to them. Gentle patting on the tummy and ‘shhsing’ does a wonderful job.

7. Learn Your Little One’s Sleep Cues And Act On Them

During a sleep regression, your little one may need more sleep during the day to make up for broken nights. Increased physical activity and abilities can make your little one more tired than usual too. 

As they adjust to their new skills you will need to act upon sleep cues to avoid them becoming overtired.

Common sleep cues include: yawning, rubbing eyes, clenched hands, glazed eyes, being distracted, pulling ears and becoming withdrawn and less social.

8. Make Up For Poor Nighttime Sleep With Extra Naps During The Day

Let your little one sleep whenever they need to during the day to avoid them becoming overtired. Knowing how much sleep your baby needs in a 24-hour period and then calculating how much daytime sleep they need will help enormously too.

Never try and keep your little one awake during the day in the hope they will sleep better at night. It will only backfire on you!

9. Make Their Sleep Space More Conducive To Sleep

Now your little one getting older they will be more easily woken by sleep distractions and noise. So, darken the bedroom using blackout blinds and use a nightlight. 

During a 15 month sleep regression your little one needs to be sleeping in a calm, dimly lit room. 

Using a white noise machine can eliminate background noise from disturbing their sleep too. They will help to ensure that sudden changes in noise will have less of an impact on your sleeping toddler.

My Top Pick
Dreamegg White Noise Machine - 21 Soothing Sounds

White noise machines are a game-changer for your little one's sleep and having one that plays all night is a must. With a long-lasting battery, this compact and stylish white noise machine contains 21 non-stop relaxing noises, which will lull your little one to sleep night after night, no matter where you are!

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10. Dress Your Little One In The Correct Sleep Gear

Ensure your 15 month old is dressed appropriately for the time of year.

I find sleeping bags are the best for this age group. And as they come in different tog weights, you can always find one that works for your location and time of year.

Tommee Tippee GroBags

Another great sleepwear range with sleeping bags to suit all ages and seasons. The easy to follow tog guide used in conjunction with the GroEgg room thermometer will give you peace of mind that you have chosen the perfect sleep attire for your little one.

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11. Help Your Little One Practice New Skills

It is important that you give your toddler plenty of opportunity to practice any new skills during wake times so that they are not desperate to do so when they should be sleeping. 

Provide them with toys to help them walk, opportunities to learn to climb safely, play with construction toys such as building blocks and try simple puzzles too. 

Read lots of books to encourage speech and cognitive development too.

Paula's Pick
Lovevery Building Block Set

Possibly the most comprehensive wooden block set ever created!

This beautiful and brilliantly designed wood block set promotes spatial, language, and problem-solving skills through bright and solid wood building blocks, planks, shapes, people, magnetic wheels and dowels with a toggle string. All are safely kept in a wooden storage box and a cotton drawstring bag for storage at the end of a busy day!

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Frequently Asked Questions About The 15 Month Sleep Regression

Looking for more information about the 15 month sleep regression? Check out the most commonly asked questions here.

Is There A Sleep Regression At 15 Months?

While there are certain ages at which sleep regressions are more common, the truth is that sleep regressions can happen at any time. 

So, yes there can be a sleep regression at 15 months of age.

Why Is My 15 Month Old Waking Up At Night?

If your 15 month old has been sleeping beautifully and suddenly starts waking at night this may be due to a number of triggers including teething or achieving a developmental milestone, starting daycare or changing sleep needs.

While you should always rule out any illness that may be affecting your little one, if all is well then you should deal with your little one’s nighttime waking and or nap resistance as a sleep regression and follow the tips listed above.

How To Navigate 15 Month Sleep Regression And Separation Anxiety?

Separation anxiety is a common cause of sleep regression but luckily there are things you can do to help your little one through this phase:

Take a look at this post for other handy tips on how to handle separation anxiety: Why Does My Toddler Follow Me Everywhere?

Do All Toddlers Experience A 15 Month Sleep Regression?

No, not all toddlers will experience a 15 month sleep regression. They may have already had one or they may have missed previous ones and are now experiencing a sleep regression for the first time due to any of the reasons listed above.

What Developmental Leap Happens At 15 Months?

At 15 months of age, your little one is likely to experience the following developmental leaps:

With all this activity going on in your little one’s development, they may easily find it hard to wind down and fall asleep or stay asleep… thus triggering a sleep regression.

How Will I Know When The 15 Month Sleep Regression Is Over?

You will know when the 15 month sleep regression is over because your toddler will begin to fall back into a regular nap and nighttime sleep routine.

Bear in mind that the new schedule may look slightly different from what they were doing before the regression hit as regressions are often a transition between sleep schedules changing.

To learn more about what to expect from your little one’s sleep schedule, read this post: 15 Month Old Sleep Schedule

Should I Let My 15 Month Old Cry It Out?

No. Letting your 15 month old cry it out is not going to cure a sleep regression or make it pass any more quickly. 

Sleep regressions are challenging and you will need to be patient and help your little one through this tricky phase by following the guidelines outlined in this post.

When Do I Need To Talk To A Doctor About The 15 Month Sleep Regression?

If you are unsure if your little one’s change in sleep patterns is due to a sleep regression, watch for the following signs. If they are present then you should consult a doctor:

If your little one has a persistent fever or a cough which is waking them at night you should also consult a medical practitioner.

Further Reading

To learn more about sleep regressions and to prepare yourself for any future ones, read the following posts:

  1. 18-Month Sleep Regression
  2. 2-Year Sleep Regression
  3. Sleep Regression: What, Why, And How To Survive It!

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Author Image Bio
Paula McLaren is the founder of Teething to Tantrums and a highly qualified childcare expert with over 40 years of experience as a Norland Nanny. She holds a BA (Hons) in Early Years Development & Learning (0-6 Years) and the prestigious Norland Diploma. Paula has worked as a night nanny, run a successful daycare center in London, and helped raise countless children using her tried and tested developmental and guidance methods.

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