Why is is so hot in September? UK prepares for record-breaking heat

September is unseasonably warm so far, following on from a cool August (Yui Mok/PA Wire)
September is unseasonably warm so far, following on from a cool August (Yui Mok/PA Wire)

London is preparing for more days of hot weather, as Temperatures are set to hit highs of 31C in the capital on Thursday September 7, and are likely to be in the late 20s over the rest of the week.

This follows on from a disappointingly chilly August across the UK, an unusual way around as August is usually the hottest month of the year, before September starts to calm down as we head into autumn.

The Met Office predicted the warmth and humidity will continue across the south-eastern parts of the UK throughout the rest of the month.

However, a cold front will also bring some cooler, fresher conditions with it, as well as some heavy, thundery rain and “generally more changeable” conditions.

But why are we getting these unusually hot and humid conditions in London? Here’s a look at what’s causing the unseasonable weather.

Why is it so hot in September?

As recorded by the Met Office, the high temperatures are being caused by tropical storms pushing high pressure into the UK.

When the atmospheric pressure increases over any certain area, it means that air will sink through the atmosphere. As the air falls, it gets compressed.

On average, temperatures will increase by 1C for every 100m that the air falls.

Why are we having a heatwave in the UK?

The tropical conditions causing pressure mean that not only are we experiencing higher temperatures but also humidity.

This could result in foggy conditions, with intermittent fog patches expected in rural areas in particular. Sunshine may be hazy, as the increased pressure causes air pollution and smog to sink closer to the ground. These particulates can cause temperature increases.

Saturday will be the hottest day of the week this week in London, reaching highs of 31C before dropping slightly to highs of 30 on Sunday.