Parts of Scotland could get close to a temperature record set 125 years ago with another day of sweltering heat in store.
The hottest June day north of the border was 32.2C (89.9F) at Ochtertyre in Perth and Kinross in 1893.
The Met Office said it is possible the mercury could soar above 30C (86F) once again on Thursday.
“I think 32.2C (89.9F) is just a bit too high, but it could come close.”
The predictions come after temperatures soared to 31.3C (88.3F) in Aviemore in the Highlands on Wednesday afternoon, making it the hottest day since June 1995, when the mercury reached 31.5C (88.7F) in Renfrewshire.
By 9am on Thursday, temperatures at Drumalbin in Lanarkshire had already hit 22.4C (72.3F).
In Kinbrace in Sutherland, readings had touched 22.1C (71.7F) by the same point.
Forecasters predict the areas inland and to the west will see the hottest temperatures as the day progresses.
Ms Diamond said: “The warmest areas are going to be away from the north and the east coast because that is where the wind is coming from. Areas away from that further inland will be the warmest.
“Aviemore seems to be a bit of a hotspot in this particular set-up.
“Glasgow is looking at 29C (84.2F), 30C (86F), possibly even 31C (87.8F) today.
“In contrast – not that it’s cold – but Edinburgh is 25C (77F) or 26C (78.8F), a five or six-degree difference.”
She also revealed that Scotland is one of several spots in the running to record the highest temperature of the day in the UK.
“Of interest, an average maximum temperature for Scotland for June is 15C (59F), so we’re almost double that,” she added.
Meanwhile, Police Scotland has issued a warning about the potentially fatal consequences of leaving animals in vehicles in this weather.
The force said on Twitter: “Please do not leave your pets in the car, even if only popping to the shops – cars heat up v quickly. The temp in a parked car, even in the shade with open windows, can rapidly reach a level high enough to seriously harm or kill your pet.”
On Wednesday, Scots flocked to beaches and parks as Scotland basked in its hottest June day in more than two decades.
The mercury then reached 30.1C (86.2F) at Aboyne in Aberdeenshire, however in general the western side of the country was hottest with temperatures of 29.2C (84.6F) in Glasgow and 28.6C (83.5F) in Tyndrum.
Passengers also faced travel disruption in the hot weather on Wednesday after all trains from Glasgow Central high level were cancelled due to “multiple points failures” near the station.