April brings the restlessness of spring. But June is something else entirely. Three things happen at once:

The light.
In the UK, summer evenings can stay light until around 10 p.m., with daylight returning from about 4:30 a.m. For a child whose sleep system is largely regulated by light and darkness, this can be a real challenge. Light suppresses melatonin production, meaning the body simply does not receive the same biological signal that it is night.

The heat.
Research shows that the optimal sleep temperature for babies and young children is lower than many parents expect, and that elevated room temperatures can affect sleep quality. An overheated body has more difficulty entering the deep sleep that provides real restoration.

The routines.
Summer brings holidays, family visits, late evening meals and days that look very different from usual. Predictability — one of the most important elements of a child’s sleep environment — suddenly becomes harder to maintain.

For a child, predictability is not about exact clock times — it is about sequence and recognition. When familiar signals disappear — the dim light at the right moment, the same movement, the same sound — the nervous system loses the anchors that usually help the body shift from activity to rest.

This can show up as extra night wakings, longer bedtimes or shorter naps — not because the child is “difficult”, but because the familiar cues are missing.

The relationship between light and melatonin is well documented. Light — especially blue light — signals to the brain’s pineal gland that it is daytime and suppresses melatonin production.

For adults, the sleep system is more mature and resilient to external disturbances. For young children, the biological system is more direct: darkness means sleep, light means wakefulness.

This means blackout solutions in summer are not excessive — they are a simple and highly effective way to support a child’s natural sleep rhythm. Not as a replacement for good routines, but as the framework that makes those routines possible.

Heat Affects Sleep Biologically
Light is the most visible summer challenge — but heat is just as important for sleep quality, and often harder to manage.

To fall asleep, the body’s core temperature needs to drop. This biological mechanism is well documented: the body begins releasing heat through the hands and feet in preparation for sleep, and the core temperature gradually decreases.

In a warm bedroom, this process is disrupted because the body has greater difficulty releasing heat into the surrounding environment.

For babies and young children, who are not yet able to regulate their body temperature as effectively as adults, the effect is particularly noticeable. Light materials, good airflow and a cool sleep environment support the body’s natural temperature regulation — and therefore the child’s ability to reach deep, restorative sleep.

A white noise speaker can also help mask the sounds that come with summer — neighbourhood gatherings, cars with open windows, birds singing at dawn. A stable sound background creates more consistent sleep conditions, even when the world outside is wide awake.

“Dad Does It Differently — And It Works”
Pernille Aagaard, Project Coordinator at Witt Denmark A/S and mother of two boys, recognises this dynamic from her own family:

"I’ve always had a plan. Times, sequence, the conditions that need to be in place before we put the boys to bed. My husband doesn’t have a plan — he has an approach. He takes the situation as it is, finds the nearest dark corner, turns on the cradle bouncer and sits down beside them. It’s not the same as my way. But the boys sleep. And I actually think they can sense that dad isn’t worried about whether it will work.”

Flexibility Is Not the Same as Chaos
There is a difference between abandoning routines and adapting them. Research on children’s sleep suggests that it is not the precise timing that creates security — it is repetition.

The same actions, in the same sequence, send the same calm signal: now it’s time for sleep.

This means a summer routine can look different from a winter routine — and still work. A baby hammock packed for the holiday creates the same familiar sleep environment whether the child is at home or in a rented summer house. The rhythmic movement from a cradle bouncer is the same in July as it is in January.
Predictability is not about clock times. It is about recognition. And that is something you can bring with you — wherever summer takes you.

Fathers do not always follow the sleep ritual exactly as the books describe. They improvise, simplify and find shortcuts that sometimes turn out to be more direct than the carefully planned approach.
And in a summer when the light refuses to fade and routines are under pressure, the ability to adapt without losing the essentials — calm, presence and the familiar repeating movement — may be the most valuable thing of all.

Happy Father’s Day to all of you who find your own way to calm.