What is a tropical night? London faces uncomfortable overnight heat in May

This weekend, parts of the country are experiencing their highest-ever recorded May temperatures, with the mercury soaring to around 32C in the capital on Sunday. It’s expected to get even hotter on bank holiday Monday and Tuesday, with some weather forecasts predicting highs of 34 degrees in the city.

Unfortunately, there won’t be much reprieve overnight either, with the temperature expected to remain high even after the sun has set.

On Sunday night, it is anticipated that the overnight temperature won’t drop below 20C – the first time this year that London will have recorded such high heat.

It’s also predicted that the country will face an increasing number of tropical nights in the coming years, as we brace for more extreme weather due to climate change.

So what exactly is a tropical night – and what’s the best way to get through it?

To put it simply, a tropical night is the name given to a night when the temperature doesn’t drop below 20C.

Although tropical nights are common in tropical parts of the world, more and more have been recorded across Europe in recent years. The UK doesn’t tend to have tropical nights unless we’re experiencing a heatwave like we are this week.

According to the Met Office: “While often associated with warmer climates, recent studies show that the UK is now seeing more frequent occurrences of these events, particularly during heatwaves.”

In the UK, tropical nights have become more common in the last few years. And in 2022, the country recorded three tropical nights in a row, marking a new milestone in UK weather.

While many people live comfortably with tropical nights, the issue is that not all UK houses are well equipped for high temperatures. Those living in poorly ventilated homes without air conditioning may find sleeping very hard unless they have a fan.

These tropical nights also pose considerable health risks, as people may struggle to regulate their body temperature, which can lead to cardiovascular stress.

According to the Met Office: “Studies have shown that high nighttime temperatures are linked to increased mortality, particularly among older adults and those with pre-existing health conditions.”

We are definitely going to see tropical nights more often in the UK because man-made climate change is accelerating the extreme warming of our planet.

A Met Office study found that the chances of the UK experiencing three consecutive tropical nights “have increased significantly” and that the probability of that sits around 20% per year.

Experts warned that adaptation strategies will be vital in the future, especially in buildings that tend to retain heat overnight. The UK should work towards improving building ventilation and supporting vulnerable communities.

In order to get a good night’s sleep during the warmest nights of the year, it’s important you try to make your sleeping setup as comfortable as possible.

Unfortunately, only 5% of homes in the UK are thought to have air conditioning, so you’ll probably have to think of more creative ways to stay cool.

Aside from investing in a fan and keeping a glass of water by your bed, here are some added tips that can help you get through the sweltering nights.