These tips are simple to put into practice and helpfully effective, says journalist Jane Knight

You can’t help feeling happier once the days lengthen and the mercury rises, but summer doesn’t feel nearly as much fun when you’re struggling to get a good night’s rest. It’s hard when the prerequisites for good sleep – a cool, dark, quiet room – are all thrown out of the (open) window. “Higher temperatures and light nights mean that your circadian rhythm – your internal body clock – can get out of sync,” says Dr Zoe Gotts, an insomnia specialist at the London Sleep Centre, who has a doctorate in sleep psychology. Here’s what you can do to help.

Those warm nights mean it’s harder for your body temperature to drop by the 1-2 degrees needed to trigger sleep. One of the most surprising ways to achieve this in summer is to have a warm bath or shower 60-90 minutes before bedtime; if you can’t face that, a footbath works, too. “The paradox is that you heat yourself up to cool down,” says Dr Gotts, explaining that the peripheral blood vessels dilate, sending more blood to the skin surface and extremities, where it cools more quickly. Studies show that baths help people drop off 10 minutes more quickly on average and enjoy better-quality sleep.

Once asleep, you need to maintain a cooler body temperature for sufficiently restorative slumbers. I know from spending many tropical nights in hotels as a travel journalist that air conditioning set at 18°C works for me. At home, create a DIY air conditioning unit using a fan with a container full of ice or damp towel in front of it. Make sure you close your bedroom curtains when the sun is strong, open windows in the evening and use natural-fibre sleepwear and bedding for their wicking qualities.

Early-dawn light is likely to wake you, so it’s worth investing in black-out blinds or curtain linings. “As you reach the early hours of the morning your drive for sleep is already quite low as you have partially sated your need,” explains Dr Allie Hare, consultant in sleep medicine and president of the British Sleep Society. “You’re more easily aroused by light and it’s more difficult to re-establish sleep.”

At the other end of the day, it’s much harder to drop off because longer, lighter evenings delay the release of sleep-inducing melatonin from the pineal gland, shifting our natural body clock. Try doing outdoor activities, such as gardening or exercise, earlier in the day, and draw the curtains early when you’re at home, because melatonin production works on cues from the eyes. Dr Gotts suggests giving your brain a psychological prompt to switch off by dimming the lights and perhaps lighting a candle.

Flinging open your bedroom window might let the heat escape, but it dials up the volume on the dawn chorus, while traffic noise can be distracting. If you’re using a fan, the constant noise can drown out outside sounds, but the item that’s helped most with my year-round insomnia is a small white-noise machine, which costs less than £50. Its range of sounds include pink noise, which is white noise with reduced higher frequencies and is akin to the sound of steady rain, and brown noise, which lowers the higher frequencies even more to the roar of a river. “They can be really useful to even out background noise,” says Dr Hare, explaining that the brain only becomes alert to sudden noises that might signal danger. “Some people prefer earplugs; there are a lot of more effective ones now.”

It’s easy to go into holiday mode in the summer months, staying up late, eating at silly-o-clock and indulging in too much rosé. “Make sure you stick to a routine even through the longer days. Don’t deviate too much just because it’s summer,” says Dr Gotts. What about the latest TikTok trends to drink lettuce water or sour cherry juice – both widely available in summer – to aid sleep? “The evidence of any foodstuffs promoting sleep is pretty poor,” says Dr Hare. “You’d have to drink an awful lot of cherry juice.” She counsels against eating late, which can result in indigestion and reflux. And heavy drinking is known to disrupt sleep quality. But there is some good news: “The odd glass of rosé on a summer evening isn’t going to be a problem”, concludes Dr Hare. Cheers to that!

Jane Knight is former travel editor of “The Times” and her work features in “The Telegraph”, “The Financial Times”, “Condé Nast Traveller” and other publications.