Met Office weather update: Fourth hot spell of the year arrives - but warning over rain and thunderstorms

Today is set to be a warm day with temperatures rising up to 29C at most, before peaking potentially at 30C in London tomorrow.

The weekend, however, is looking unsettled with the chance of heavy rain and thunderstorms. Before that, though, a yellow thunderstorm warning has been issued for much of Northern Ireland from 11am until 8pm today - there’s set to be between 30mm and 40mm of rainfall in just a few hours, the Met Office says.

Temperatures will drop over the weekend.

Met Office forecaster Jonathan Vautrey said: “We’re starting to see south westerly winds come in, that’s bringing in hotter and more humid conditions, particularly in southern areas, we are going to see temperatures climbing again.

“There is the potential for 30C around the London region by the time we reach Friday, other areas around south east England will push towards high 20s.

“Average temperatures in July for the south east is around 23C, so it will be about 5C above average. On Thursday it will probably creep up to around 28C in London, maybe 29C in more central England. Friday is looking to be the peak of the current hot spell.

“This heat is not going to be as widespread as what we’ve just come out of, areas to the north aren’t going to be seeing the same highs.

“The heat we had last time was home grown, it wasn’t that humid, but because this heat is coming in from the south westerly direction, it is more humid. It’s going to be feeling more sticky.”

The weather is set to turn unsettled through the weekend, with a chance of some heavy showers and thunderstorms across the UK, but detail on that is currently low, Mr Vautrey said.

Weekend high temperatures are still expected to reach 28C or 29C on Saturday and 25C on Sunday.

There is a “small probability” a localised area will get the three-day category for a heatwave this week, but for most people it will be more of a “hot spell”, Mr Vautrey added.

Southern Water has become the latest company to bring in a hosepipe ban, to protect rare chalk stream habitat, as England battles exceptionally dry weather.

The company said restrictions on hosepipes for activities such as watering gardens, filling paddling pools or washing cars would come in for households in north and west Hampshire and the Isle of Wight from Monday.

It is the latest announcement by water companies bringing in hosepipe bans in response to the driest start to the year since 1976 for England.

Rainfall across England was 20% less than the long-term average for June, which was also the hottest on record for the country, with two heatwaves driving unusually high demand for water, the Environment Agency has said.

Drought was declared in East and West Midlands on Tuesday, with the region joining swathes of northern England in drought status.

Yorkshire Water became the first major water company to bring in a hosepipe ban which came into effect last Friday. South East Water has announced a hosepipe ban in Kent and Sussex from Friday, and Thames Water is bringing in a ban from next Tuesday for customers in Oxfordshire, Gloucestershire, most of Wiltshire and some parts of Berkshire.