Temperatures could reach the mid-30s in parts of the UK this week as forecasters said that Britain should brace itself for its “first properly hot summer’s day”. The coming months will also bring heatwaves which the Met Office has previously warned are becoming more likely due to climate change and the higher concentrations of CO2 in the atmosphere. “There’s not been much in the way of exceptionally warm days or hot days yet this year, but that is set to change,” the Met Office’s Steven Keates said. “We’re set to see probably a brief spell of hot weather at the end of this coming week.” In the south-east England temperatures could hit 32C (89.6F) on Friday but could even reach into the mid-30s, the Met Office said. This would make the area hotter than the Canary Islands, Portugal, Jamaica, Costa Rica and Cyprus. This would also mean that at some point later in the week the country will get the hottest day of the year so far. The previous warmest was 27.5C (81.5F) recorded at Heathrow on 17 May. Keates added that we should beat the record “comfortably on Friday”, but could get close to or exceed it on Wednesday or Thursday. He also warned that the country could face heatwaves between June and mid-September. A heatwave is defined by the Met Office as “at least three consecutive days with daily maximum temperatures meeting or exceeding the heatwave temperature threshold”. This threshold varies by county. “We think at the moment it will be warmer than average with an increasing likelihood of heatwaves,” Keates said. “There have been no heatwaves so far this year … the greater likelihood is that it’s going to be the further south, south-east, you are.” In March, the Met Office updated its heatwave thresholds due to the impact of the warming climate. Eight counties – from Surrey to east Yorkshire – were changed to reflect “an undeniable warming trend for the UK”, the Met Office said. Dr Mark McCarthy, the head of the Met Office National Climate Information Centre, said: “Although heatwaves are extreme weather events research shows that climate change is making these events more likely. “A scientific study by the Met Office into the Summer 2018 heatwave in the UK showed that it was 30 times more likely to occur now than in 1750 because of the higher concentration of carbon dioxide in the atmosphere.” NHS hot weather advice suggests that people stay out of the sun between 11am and 3pm, keep hydrated, use sunscreen and wear loose-fitting clothes.