Aidan Mcgivern - Sleep Club Safer Sleep 04/06/18

Sleep tight – what controls night-time temperatures? By Aidan McGivern

Many different factors influence the temperature at night. Inland temperatures tend to drop faster than coastal locations due to the moderating influence of the sea. Rural air tends to cool quicker than urban. Even the type of soil has an impact. Met Office Meteorologist Aidan Mcgivern describes the factors that determine how much sleep he, and his young daughter, might get.

The first weather prediction I made when I joined the Met Office more than ten years ago was for the minimum temperature in Exeter that night. During my training, I learnt how to construct a temperature curve that could predict the temperature at any point during the night. Taking into account the long November night, the clear skies and the gentle breeze, my temperature curve resembled a beautiful upside-down-S shape and I had full confidence in my prediction. The next morning, I discovered I was three degrees out. The temperature had fallen quicker than expected, my curve wasn’t steep enough.

Fast forward to April 2017 and I am just as concerned with temperature at night. But this time it’s because of my five-month old who, for everyone’s benefit, really could do with having a long and comfortable night’s sleep. The temperature in her room at bedtime is perfect, but the skies outside are clear and the winds are light. My thoughts return to my very first forecast and the temperature curve.

On a still, cloudless night, temperatures do not tend to fall at a constant rate. The air outside starts cooling slowly following the warmest time of day, typically mid-afternoon. Cooling then accelerates after sunset before slowing again as dawn approaches. The lowest temperature often occurs half an hour after daybreak, due to a time lag. This is the temperature curve, the upside-down-S shape.

Behind the curve

Many different factors will influence the shape of this temperature curve.

Of course, the weather overnight is not always clear and still. Any clouds in the sky will act as a blanket, stopping warmer air from escaping into the heavens. A breeze will have a similar effect, helping to mix cold air close to the ground with milder air elsewhere, preventing a steep temperature curve.

The weather, especially in the UK, is notoriously changeable. Overnight temperatures vary not just from season to season and from day to day but can also fluctuate dramatically within a single night.

These sudden changes can be brought by weather fronts. You may have seen these abstract colourful lines on weather maps. The blue lines with triangles – cold fronts – can clear the air and cause a steep drop in outside temperature. The red lines with semi-circles – warm fronts – can increase the humidity to uncomfortable levels, especially during summer.

Maintaining a comfortable temperature

With the temperature outside varying depending on location, cloud, wind, time of year and weather fronts, it is not surprising that it can be so difficult to maintain a constant temperature in your child’s bedroom.

Thanks to modern insulation, heating and air conditioning bedroom temperatures are unlikely to change through the night as much as outdoor temperatures. But it’s still useful to understand how abruptly the temperature outside can rise and fall and how this might impact your baby’s sleeping patterns.

By April 2017, I no longer needed my less than reliable temperature curve. Like many sleep-deprived parents, I was now an expert in the precise temperature variation in my little girl’s bedroom throughout the night – whatever the weather.


Top Stories

  • Mummylinks Blog Link

    #ShoutieSelfie For Maternal Mental Health

  • Is my newborn napping enough?

  • join our sleep club

    Sign up to join our expert parent panel, be the first to hear about new products and get exclusive offers

    email address...

    Subscribe to our Newsletter

    We'll keep in touch with all the very latest information from The Gro Company including:

    • Fabulous competitions - to win gorgeous goodies
    • Regular offers and special promotions on our award-winning range
    • Exclusive previews of exciting new products

    Join us on Facebook and Twitter too, for all the latest chat, news and competitions.

    Our FREE Grobag prize draw is drawn monthly and we will be in touch if you are the lucky winner!*

    *Please be aware we are unable to ship prizes outside of the EU.

  • Elephant_City_Groswaddle_Hip_Healthy (1)

    What is swaddling? Is it safe?

  • Ollie_the_Owl

    What is white noise?

Shop now

The Gro Company’s entire range is available to buy online at ‘The Gro Store’. Buy any 2 items save 10% and receive FREE delivery on orders over £10.

Gro Store
Gro - Ipad

Find A Local Stockist