How is this heatwave different to the one we saw in July?

Another month and another extreme heat warning issued by the Met Office, but this one is different to the heatwave we saw in July this year where temperatures reached 40.3C.

On Tuesday morning, the Met Office issued yet another Extreme heat warning for much of England and parts of Wales, where temperatures are expected to peak in the mid 30s.

Extreme heat warning issued by the Met Office - Tuesday 9th August Credit: ITV Weather/Met Office

Adverse health effects are likely to be experienced by the vulnerable, with some likely to experience some adverse health effects including sunburn or heat exhaustion (dehydration, nausea, fatigue) and other heat related illnesses.

Will this heatwave be as hot as the one we saw in July?

To put simply, no. The hot weather we saw in July was exceptional. The jet stream played a major role, pumping hot air from Spain, Portugal and northern Africa, towards us adding to the home grown heat over the UK. This allowed the temperatures to rocket to 40C, something the UK has never seen before.

The set up we have currently is different. The Jet Stream, that first flowing ribbon of air high in the atmosphere is much further north of the UK. This is taking rain bearing weather fronts away from us. A large area of high pressure has been able to develop, which is bringing lighter winds and clear skies.

This set up is allowing the temperatures to steadily rise day on day - home grown heat. However, as we move towards the end of this week, the hot air over France and German, will be pulled towards the UK, allowing our temperature to have a bit of a boost into the mid 30s.

In summary, this heatwave won't be as hot, it won't be as humid and the nights won't be as warm. However, the prolonged heat will make it difficult to sleep at night as our homes are designed to retain the heat and there is still the risk of heatstroke and heat exhaustion. It's important to avoid the midday sun, try and stay cool and keep yourself well hydrated.

  • ITV Meteorologist Chris Page explains why this heatwave is different to the one we saw in July.

Will we see 40C during this heatwave?

Although it's not impossible, it's not very likely. Compared to July, the sun isn't as strong and day length has been shortened slightly too. Combined with the fact the air is coming from a cooler source region (France and Germany) compared to the heatwave in July (Spain and Portugal).

When will it rain next?

After the driest July since 1836 for parts of the south-east of England, the UK’s gardens and farmers are crying out for some rain. August too has seen a rather dry start to the month which increases the risk of wildfires as the ground is so tinder dry.

Odiham in Hampshire is one of the driest places, where it hasn't rained since July 1, 2022. And it's not just at the ground but from space it's more obvious.

Images from space show how tinder dry the south of England are. The image is from 19th July 2022 Credit: NASA Worldview
The lush green landscape of July 2021 Credit: NASA Worldview

Current computer models are suggesting some heavy showers are possible on Sunday, but these are likely across the Midlands and Wales. For more widespread rain or showers we have to look ahead to Monday or even Tuesday next week but at this time scale confidence becomes lower. It's something meteorologists are keeping a close eye on.

Are these extreme temperatures due to climate change?

Recent studies from the Met Office show in a world where the climate was unaffected by man made climate change, it would be virtually impossible for temperatures in the UK to reach 40C. However, climate change is already making UK heatwaves more frequent, more intense and longer lasting.