The UK is likely to experience the hottest weekend of the year so far, with many parts of the country on track for a heatwave, the Met Office has said.

Warnings about the extreme heat have been issued by both medical authorities and vets, urging people to keep the vulnerable and animals safe.

Temperatures are expected to hit highs of 31C in London and could exceed those on the continent, with 29C predicted in Ibiza on Sunday.

Even areas further north including Hull and Newcastle are expected to reach the mid to high 20s as the weekend progresses with temperatures “building day-on-day”, according to the Met Office.

The criteria for an official heatwave is three days of sustained high temperatures but this can vary across the country.

Andy Page, meteorologist at the Met Office, said: “The extension of the Azores high is the principal reason behind the UK’s current weather pattern, which will see much of the UK reach heatwave thresholds over the weekend and into early next week.

“High temperatures will remain in the forecast well into next week, but there’s a risk of isolated heavy showers in the south of the UK on Monday and Tuesday, although it should be largely fine for most areas.”

It comes as a heat-health warning was issued by Public Health England (PHE) ahead of the predicted extreme temperatures.

PHE advised people to look out for those who may struggle to keep cool and hydrated, such as older people and those who live alone.

All dogs can overheat if left without water or in hot conditions for too long

Emergency animal care provider Vets Now also warned rising temperatures could increase the risk of heat stroke in dogs.

The vet service sees a spike in callouts as the weather warms up and has warned that temperatures above 20C put dogs at risk, and that survival rates for dogs with heat stroke is just 50%.

Dave Leicester, head of telehealth at Vets Now, said: “All dogs can overheat if left without water or in hot conditions for too long. So on hotter summer days it’s best to walk your dog in the morning or evening when it’s cooler.”

The warnings come after a week of flash flooding in the south east of England, causing disruption to transport in London.