Temperatures in parts of the UK exceeded 28C on Monday as the country saw its hottest day so far this year, forecasters have said.

It comes as warmer weather and likely heatwaves forecast for parts of the country this week offer a “welcome boost” to the hospitality sector after a drizzly spring saw footfall wane, according to industry leaders.

The hottest temperature recorded on Monday was 28.3C in Wisley, Surrey, the Met Office said.

This is the warmest temperature recorded so far this year, overtaking a 27.5C reading taken in Chertsey, also in Surrey, in May.

London saw a peak recording of 27.4C at St James’s Park, while temperatures rose to 26.9C in Aberdeenshire, Scotland and reached 25C in Northern Ireland.

Temperatures in London are forecast to hit peaks of 31C on Wednesday, with much of south-east England basking in the mid-20s for the first half of the week.

It marks a break from the rainy spring, which saw 32% more rainfall than the average in England and Wales according to the Met Office, and hampered businesses reliant on tourism or high street foot traffic.

One veteran ice cream seller, known to her customers in West Sussex as Mrs Whippy, welcomed the “wonderful” news of warmer weather.

Katy Alston told the PA news agency: “It has a massive impact.”

Ms Alston has been in the ice cream trade for 20 years and runs Pinks Parlour near the beach in Bognor Regis, West Sussex.

The former Ice Cream Alliance president added: “The wonderful thing is, at the moment, the forecasting is this really hot weather.”

“What we notice, once the weather’s good, is everyone goes into holiday mode – so they eat ice cream, they come out, they spend longer out.”

Oli Claydon, a Met Office spokesperson, said “it won’t be sunshine for everyone”, but will still be warm even where there is cloud cover during the week.

“We might see the occasional shower in parts of Northern Ireland and Scotland, where there will be a little bit of cloud through (Tuesday), but otherwise clearer skies in the South East and that’s where we’re going to see the highest temperatures,” he added.

The heatwave threshold is met when a location records at least three consecutive days with maximum temperatures exceeding a designated value, according to the Met Office.

This is 25C for most of the UK, but rises to 28C in London and its surrounding area, where temperatures are typically higher.

Emma McClarkin, chief executive of the British Beer and Pub Association, said sunshine and warm weather meant pubs “sell more beer”.

She added: “The last period of sustained warm sunnier weather way back in September last year saw average increased sales of almost 20% and this is crucial for both brewers and pubs after the more challenging winter months and recent wet weather.”

Jenni Matthews, head of marketing and insights at MRI Software, said independent retailers and high street businesses such as pubs and restaurants are particularly reliant on the increased footfall caused by warmer weather.

“With warmer weather, it’s normally the high streets that tend to benefit because they’re outdoor retail destinations and people want to make the most of the weather,” she said.

“And I think what’s so impactful about last week and what we’ve got coming up this week, is that we’ve also got the Euros, we have the Taylor Swift concert in London, and they both contributed to footfall massively within high streets last week.”

Data released by the real estate company on Friday showed an average footfall increase of 5.5% when compared with the week before as high street activity shot up by 11.8%.

Kate Nicholls, chief executive of trade body UKHospitality, said: “The weather often plays an important role in people’s decision-making and the current spell of warm weather will be a welcome boost for hospitality venues across the country, with people keen to get out and make the most of the sunshine.

“Businesses across the sector will be hoping for a strong summer to offset the impact of the ever-rising cost burden that they are facing,” she added.

The UK Health Security Agency (UKHSA) has issued yellow heat-health alerts for most of England, warning the warm conditions could pose a risk to vulnerable individuals.

However, the heat is only expected to last until Wednesday with heavy showers, thunderstorms and persistent rain possibly returning in the west as the week goes on.

“There will be a little bit of rain and cloud through Thursday,” Mr Claydon said.

“But it’ll actually be quite pleasant, although temperatures will still be a little cooler and closer to average – the weather will still be fine and there will be a lot of dry weather around.”